Professional firms need to take great care in their dealings with expert witnesses in negligence cases or run the risk of handing an advantage to the other side.

In a recent construction case one party was forced to hand over documentation about an expert witness’ opinion after it changed expert mid-case.

Allen Tod Architecture accused structural engineer, Capita Property and Infrastructure of professional negligence in relation to a property redevelopment.  The case went to court where the parties were granted permission to call expert structural engineer witnesses.

Allen Tod’s legal team selected an expert, but lost confidence in him after he was slow in producing his report.  It asked the court permission to change to a new expert witness to give evidence.  Capita’s defence team immediately asked for all of the documents and drafts setting out the original expert’s opinion to be made available.

Allen Tod’s team provided the expert’s original report, but declined to disclose any further material arguing that it was privileged. It said that it had already disclosed sufficient material and that it had not been guilty of ‘expert shopping’ – the process of shopping around to find an expert who would give a favourable opinion.

The judge ruled that Allen Tod needed to provide all the information requested by Capita, including notes and earlier draft reports.  The case shows that any dealings with experts must be considered as potentially disclosable.  “Parties should take care in communications with experts. Experts equally should be wary as to the manner in which they express their opinion in correspondence with the parties and should ensure, where the opinion is preliminary or caveated, this is clearly expressed,” wrote Sheena Sood of Beale & Company in a report for

“This case shows the dangers of changing expert mid-case,” said James Burgoyne, Director – Claims & Technical, Brunel Professional Risks.  “The judge decided that this was not a case of ‘expert shopping’ but still ruled that the earlier expert’s opinion needed to be disclosed if the claimant wanted to rely on the evidence of the new expert in court.”

Reports on the case have been published by a number of law firms, including  Eversheds, Herbert Smith Freehills and has also published a case report.