The cross-examination of a quantum expert in international arbitration is a demanding exercise for the expert and a critical opportunity for the cross-examining party. A well-prepared cross-examination can substantially undermine the credibility of an opposing expert and can recover ground that has been lost in the written reports. A poorly prepared cross-examination can entrench the opposing expert's position and reinforce the tribunal's confidence in their evidence.
Cross-examining counsel typically pursue several themes. The first is independence: counsel will seek to demonstrate that the expert has been improperly influenced by the instructing party, has accepted instructions that lacked an independent foundation, or has departed from the duty of independence in some material respect. An expert who has lost the appearance of independence has lost most of their value to the tribunal.
The second theme is methodology: counsel will probe the methodology adopted by the expert, the alternatives considered, the reasons for the choice, and the limits of the chosen methodology. An expert who cannot articulate the basis for the methodology adopted, or who cannot defend it against principled criticism, will struggle to maintain credibility.
The third theme is the underlying records and assumptions. Counsel will test the records on which the expert has relied, the accuracy of the data, the appropriateness of the assumptions, and the sensitivity of the conclusions to changes in the assumptions. An expert whose conclusions are highly sensitive to assumptions that turn out to be unjustified will see those conclusions unravel under cross-examination.
The fourth theme is consistency: counsel will look for inconsistencies within the expert's own reports, between the expert's reports and other documents, between the expert's reports and the expert's contemporaneous communications, and between the expert's reports and the expert's prior published views or expert evidence in other cases. Inconsistency is a powerful weapon in the hands of skilled cross-examining counsel.
The expert who has prepared properly will be in a position to deal with each of these themes. The expert will have documented the basis of every methodological choice, will have tested the conclusions against the underlying records, will have explored the sensitivity of the conclusions to changes in assumptions, and will have ensured consistency between every document for which the expert is responsible. The expert will also have anticipated the likely lines of cross-examination and will have prepared considered responses to each.
An equally important quality is the willingness to concede. The expert who refuses to concede points that cannot fairly be defended will lose credibility on every point in the cross-examination. The expert who concedes the points that should be conceded, while holding firm on the points that can properly be defended, will emerge with credit and with the tribunal's continued confidence. Our quantum experts at Construction Expert Witness combine rigorous preparation with the professional independence and intellectual honesty that the demands of arbitration cross-examination require.