Expert Opinion
When a dispute, an investigation or a regulatory review turns on whether a business was properly run and controlled, the legal team needs an independent view from someone who has spent a career providing them.
James Walker is an independent board chair and non-executive director and a Chartered Internal Auditor who has led internal audit teams at Credit Suisse and UBS. He offers lawyers, insurers, investors and boards independent expert opinion and expert witness work on how a business was run and controlled, from corporate governance, risk management and supervision to internal control and internal audit.
In financial services that covers banking front to back, from trading, capital markets and lending to private banking, wealth management and asset management. Beyond it, the same questions arise in any organisation, from growth companies to charities, public bodies and search and rescue. Every enquiry starts with a conflicts check, so a first call can settle quickly whether he is free to act.
Purpose
What expert opinion is for
“When something has gone wrong, the court needs to know what good looked like at the time, and whether the business measured up.”
James Walker, Founder, Lightning Oak
In many disputes the question is whether a business was properly controlled: whether its controls were sound and worked in practice, whether risks were managed and people supervised, what a reasonably competent internal audit function would have done, and what an audit committee could be expected to ask and rely on. It is judged against the rules, codes and standards in force at the time, without hindsight. A court or tribunal weighs that view with the rest of the evidence; the law, and the questions it must answer itself, stay with it.
Matters
When controls are called into question
These questions come up in courts, tribunals, arbitrations and regulatory investigations, in financial services and beyond. They reach an expert through the lawyers acting for one side, whoever stands behind them, from an insurer or a litigation funder to an investor, a liquidator or a board after a concern is raised.
01
A control that failed
Whether the controls around a failure were adequate: how the control was designed, whether it worked as intended, who supervised it, how risk management and internal audit tested and followed it up, and what the audit committee and board were told at the time.
02
Before a regulator or tribunal
How a firm’s systems and controls compared with the practice expected under the rules and guidance of the time, and what its board and senior managers could reasonably rely on from risk, compliance and internal audit, in an investigation, an enforcement case or an appeal.
03
Governance and supervision
How a board, its committees and senior managers governed and supervised the business at every level and across subsidiaries and branches, including culture, conduct, conflicts, pay and outsourcing, how issues were escalated, and what the board could normally rely on.
04
Fraud and financial crime
Whether fraud and money laundering controls were adequate. A large organisation charged with failing to prevent fraud has a defence if it proves it had the prevention procedures it was reasonable to expect, or that it was not reasonable to expect any, a question that arises long before any charge.
05
When internal audit is questioned
Whether an in-house or outsourced internal audit function, or an independent review, covered the right risks and tested, reported and followed up as its engagement and the standards of the time required, how risk, compliance and audit worked together, and what the audit committee relied on.
06
After a deal
Where a warranty or indemnity claim turns on a business’s controls or its compliance with the rules, how those controls compared with the rules and standards that applied to a business of its kind at the date the warranty was given, whether or not it was regulated.
Sectors
Banking front to back, and beyond
His experience runs deepest in investment banking: equities, and how trading businesses were supervised and governed. The sectors below are a guide, not a limit.
Trading and markets
How desks were supervised and controlled, above all in equities and equity derivatives and also in FX, rates and commodities: trade processing, product control, trade reporting and conflicts of interest.
Lending and credit
Whether credit was granted, documented and monitored as the lender’s framework required, from specialist and asset-based lending to consumer lending through intermediaries, arrears and collections.
Wealth, private banking and asset management
Whether a private bank, wealth manager or asset manager had controls that fitted the clients and assets in its care, and how complaints were handled and overseen by risk, compliance and audit.
Beyond financial services
Whether a growth company, a charity, a public body or a search and rescue team had the governance, risk management and controls its size and activities called for, judged by its sector’s codes.
The work
From a first read to expert evidence
Each role is agreed at the outset, so the line between advising a legal team and giving evidence stays clear. A matter can start with a short preliminary view and grow only as far as it needs, from private advice to a report for the court. Boards commission independent reviews, and firms acting as skilled persons for the FCA or PRA can bring him into their review teams.
A preliminary view
A short, private read of the key documents before a letter of claim, a pleading or a response to a regulator, so the legal team knows how the point is likely to stand up. It is offered for a fixed fee, with a short written or oral view by an agreed date, and whether he could later act as the expert is settled at the same time.
Advisory expert
Working privately with the legal team, sometimes called a shadow expert: framing the questions, testing the other side’s expert evidence and preparing for the experts’ discussion and trial. Whether he could later act as an expert witness in the same matter is settled at the outset, and any earlier role is disclosed.
Expert witness
An independent report for a court, tribunal, arbitration or regulator, under the forum’s rules for experts, such as Part 35 of the Civil Procedure Rules or Part 19 of the Criminal Procedure Rules, then the experts’ discussion and evidence. Once instructed, his duty is to the court or tribunal, overriding any obligation to whoever instructs or pays him.
Independent review
For a board, its trustees or an audit or risk committee: an independent view of whether the business is properly controlled, in a written report to the committee chair. Where lawyers commission it, they advise whether privilege applies, and the identity of anyone who raised a concern is protected as far as the law allows.
Experience
A career built on providing independent views
James has spent his career providing independent views of how businesses are run and controlled, first as an auditor and head of audit and now on boards. In large banks he took his findings, many of them critical, to audit committees in several countries and answered their questions, and worked directly with the FCA, the PRA and regulators in other countries.
His audit work covered all aspects of banking, front to back, across Santander, Investec, Credit Suisse and UBS, and earlier in his career included the controls against financial crime. He was Global Head of Audit for Equities at Credit Suisse, and at UBS he headed audit of the Credit Suisse UK investment banking entities, with responsibility delegated under the Chief Auditor.
On boards, he chairs a growth company, sits on an NHS trust board and has served charities as a trustee and on audit, risk, finance and investment committees. On one, he made the case for commissioning internal audit for the first time and ran the selection of its provider. He is a Chartered Internal Auditor, a Certified Internal Auditor and a Fellow of the Association of Chartered Certified Accountants.
Specialist ground
Supervision, culture and what boards are told
Three questions have run through his work in banks and on boards: how supervision and governance worked in practice, whether culture and conduct were properly controlled, and whether what a board was told deserved its trust. These are the questions many disputes come down to.
Governance at every layer
Risk management, supervision and governance ran through his audits in every role. He co-led the internal audit global methodology on supervision and governance, and has audited governance from the boardroom down to individual trading desks.
Risk and control culture
He designed the audit approach to risk and control culture that a global bank then used worldwide. He has also audited conduct, conflicts of interest and the remuneration schemes that apply to the highest earners, against the standards of the time.
Testing the headline number
At a large bank, a team reported a high compliance rate for its regulatory reporting. He showed the rate covered only the fields the team had chosen to test, not everything it reported. Management contested the finding, and it was accepted.
Independence
The same opinion, whichever side asks
“The evidence decides the opinion. Who is asking, and who is paying, never does.”
James Walker, Founder, Lightning Oak
The conflicts check runs against his board seats, former employers, clients, any transaction or review he has worked on and the firms he has worked with, including as an associate. He will disclose any current or expected work with a party or its advisers, including any internal audit provider he works alongside or competes with, and will decline any matter where a conflict, real or apparent, could affect his independence. He will not give evidence on work he carried out, reviewed or supervised, and he is available to claimants and defendants alike.
Questions
Expert opinion and expert witness work
What a legal team will want to know before a first call: what James offers an opinion on, which standards an opinion is judged against, who can instruct him and how the roles and fees work. Anything not answered here, ask him directly.
What can James offer an opinion on?
James Walker offers independent expert opinion on whether a business was properly run and controlled: whether its controls were adequate, sound and working in practice, across corporate governance, risk management, supervision, internal control and internal audit, and on how the board and its committees oversaw it. In financial services that covers banking front to back, from trading, capital markets and lending to private banking, wealth management and asset management.
Which standards is an opinion judged against?
The standards that applied at the time. In internal audit, the Institute of Internal Auditors’ Standards, replaced from 9 January 2025 by the Global Internal Audit Standards (for UK public bodies, the Public Sector Internal Audit Standards until March 2025), and the Chartered IIA’s Financial Services Code and its successor, the Internal Audit Code of Practice. In governance, the Combined Code or, from 2010, the edition of the UK Corporate Governance Code that applied, the Wates Principles where a company followed them, the Charity Commission’s guidance and the Charity Governance Code, and the codes for public bodies. In financial services, the rules of the FSA and, from April 2013, the FCA and PRA, including their systems and controls rules, the approved persons regime and, for banks from March 2016, the Senior Managers and Certification Regime; for financial crime, the Money Laundering Regulations and the JMLSG guidance of the time, and for fraud by large organisations, the failure to prevent fraud offence from 1 September 2025. How large banks applied those rules in practice is within his experience; what the rules mean is for the court or tribunal.
Can James offer an opinion outside financial services?
Yes. Whether a business was properly controlled is a question for any organisation, and the disciplines are the same. James chairs a growth company, sits on an NHS trust board, has served charities large and small as a trustee and on audit, risk, finance and investment committees, and is a Search Operations Manager with London Search and Rescue. Where a question needs specialist knowledge he does not have, he says so at the outset.
Who can instruct James?
Lawyers acting for a firm, an individual or an office-holder such as a liquidator, on either side, or for both where he is a single joint expert, including through an expert services firm working with them, in civil or criminal proceedings, regulatory investigations and appeals; for an independent review, a board, a committee or the lawyers advising them; and a firm acting as a skilled person for the FCA or PRA, which can bring him into its review team, in which case he does not act as an expert in the same matter.
Can an advisory expert later give evidence?
Sometimes. Whether he could is agreed with the legal team at the outset, and any earlier advisory role is disclosed if James later gives evidence.
How are fees set?
By the hour, or as a fixed fee for a preliminary view or a scoped review, with a written estimate for each stage agreed before work starts; rates are given on request. Fees never depend on the outcome of the matter or on what the opinion says.
Does James offer opinions on accounts or the law?
No. Whether accounts were properly prepared, or a statutory audit properly carried out, is for forensic accountants and audit specialists, and the law is for the court. Nor does he give opinions on whether advice was suitable. His opinion is on how the business was controlled, including internal audit, and how that was governed and overseen. Where a matter needs both, he can work alongside a forensic accountant.
Insights
Writing on control and accountability
Briefings for boards, committee chairs and risk and audit leaders on the standards a business’s controls are held to, and on what a court or regulator reads when it looks back. Each sets out the standard of the time and the questions a board can ask now.
What should a buyer check in an FCA-authorised firm’s governance?
Board papers show a buyer how a regulated target runs in practice, and approval from the regulator depends partly on the same governance.
What does the failure to prevent fraud offence ask of a board?
A large organisation can defend the offence by proving reasonable fraud prevention procedures, and the guidance makes prevention a board responsibility.
Start with a conflicts check
The check needs only the names of the parties and related companies, any funder or insurer involved, the law firms acting and the court or forum. Please send no documents or detail of any allegation until James confirms he is free to act; what is sent is held in confidence and used only to check conflicts. For a review, the organisation’s name is enough. If the matter is not public, or it is urgent, call first. James replies within two working days.