Independence on Trial: What the TCC Now Expects of Experts

Every expert report filed in the Technology and Construction Court carries the same declaration: that the expert understands the duty to the court and has complied with it. For years that declaration was treated as boilerplate. It is not treated as boilerplate now. The modern court reads it as a warranty, and it has shown itself willing to exclude expert evidence entirely where the warranty proves false.

The content of the duty has been settled since The Ikarian Reefer: expert evidence should be, and be seen to be, the independent product of the expert, uninfluenced by the exigencies of litigation.¹ CPR Part 35 gives it procedural force. Expert evidence is restricted to what is reasonably required, the duty to the court overrides any obligation to the party paying the fee, and the report must state the substance of all material instructions.² And since Jones v Kaney, the expert who fails in that duty can no longer shelter behind immunity from suit.³

For a long time the sanction for partisanship was rhetorical: adverse comment in the judgment and diminished weight. That era has ended. In Dana UK Axle v Freudenberg, the TCC excluded a party's technical expert evidence in its entirety, mid-trial, after it emerged that the experts had made undisclosed site visits and enjoyed a free flow of information from their client that was never revealed in their reports.⁴ The message was structural: serious breaches of Practice Direction 35 go to admissibility, not merely to weight.

Andrews v Kronospan runs on the same line. Where an expert had engaged in extensive undisclosed communications with the instructing solicitors while the experts' joint statement was being negotiated, the court revoked permission to rely on him altogether.⁵ The joint statement process, long treated by some as a private drafting exercise, is now firmly understood as a space in which the experts must be left alone.

An expert who argues the case stops assisting the tribunal. And tribunals have stopped pretending not to notice.

The construction authorities share an anatomy. In Imperial Chemical Industries v Merit Merrell Technology, the court restated the governing principles after finding that experts had approached their task as advocates for the party instructing them.⁶ In Beattie Passive Norse v Canham Consulting, an expert whose analysis departed from the contemporaneous record was dismantled in the judgment, and the claim substantially failed with him.⁷

Note what these failures have in common. None was produced by a brilliant cross-examination. Each was latent in how the opinion was assembled: a selective document diet, conclusions formed early and defended late, positions that tracked the pleadings rather than the evidence. Cross-examination merely surfaced what the working method had already built in.

The practical question is how to make independence demonstrable rather than declaratory. The answer is architectural. An opinion is defensible when every figure, every date, and every causal statement can be walked backwards to a source document, and when the methodology, including any technology deployed in the analysis, is disclosed and repeatable.