Legal Question in Civil Litigation in California

You need to disclose your expert witnesses ahead of time if any party (including you) has properly demanded an exchange of expert witness information.

Your expert's report is unlikely to be admitted into evidence unless all parties so stipulate, which they almost certainly won't. Judges and juries rely on expert *testimony* -- a term which means what it says. Except in unusual circumstances, your expert must take the stand and explain her position, after which the other parties are entitled to cross-examine her. There is no meaningful way to cross-examine a written report. That may be one reason why you want to do it, but it is also one reason why the rules don't allow it -- and why your opponents are unlikely to stipulate.

I agree with Mr. Hoffman.