Expert witnesses are frequently used to value businesses, trace property, analyze income, or evaluate retirement benefits. When a retained expert appears for deposition without having completed the necessary analysis, the opposing party may seek to exclude the expert’s opinions from trial.

Expert Discovery Must Be Meaningful

A retained expert should be sufficiently familiar with the case to explain the specific opinions expected at trial and the basis for those opinions. The deposition gives the opposing party an opportunity to understand and test that testimony before trial.

Merely appearing for the deposition is not enough. An expert who cannot explain the analysis, identify the supporting information, or state the expected opinions may not have provided meaningful expert discovery.

Tentative Opinions Can Create a Problem

An expert who says the analysis is unfinished or offers only preliminary conclusions prevents the opposing party from determining what testimony must be addressed at trial. The expert generally should not use the deposition as a placeholder while continuing to develop entirely new opinions.

The significance of the problem depends on what the expert disclosed, what work remained unfinished, and whether the opposing party received a fair opportunity to examine the expected testimony.

Exclusion May Be Requested Before Trial

When a retained expert was not prepared to provide a meaningful deposition, the opposing party may ask the court to prevent the expert from offering the undisclosed opinion at trial. Exclusion is not automatic; the court evaluates the deposition record and the circumstances of the discovery failure.

The requesting party should identify the questions the expert could not answer, the analysis that remained incomplete, and the testimony the expert later seeks to introduce.

Preparation Records Can Be Important

Deposition transcripts, expert reports, engagement terms, document-production requests, communications concerning scheduling, and materials the expert reviewed may help establish whether the witness was adequately prepared.

The party offering the expert should confirm before deposition that the expert has completed the necessary work and can explain each opinion and its factual basis.

A California divorce attorney can prepare an expert for meaningful discovery, document deficiencies in an opposing expert’s deposition, and request or oppose exclusion based on the actual scope of the opinions disclosed.