You know — of course you do — that almost any complex case calls for the help of an Expert Witness.  Possibly several.

She or he may opine about a Great Many Things, from where the product market starts and ends, to the amount of damages, and (even) to the air-speed velocity of an unladen swallow.

Lots of cases can't get through the Early Innings without an expert report.  Medical malpractice comes to mind.

Blawgletter's earliest experience with an expert reminds us of the Danger that attends the Choice of Expert.  We picked one who looked good in the Yellow Pages.  And yet he Begged to Differ with our dear client on the stand, in front of a Jury.

That seldom happens in a Big Case.  The experts must often pass the filter of Jury Trial Experience.  And need to have won more than their share of victories.

But we see Danger in the statistics.  An expert who has enjoyed some success in court tends to believe in her or his Prowess.  The expert comes to doubt critics.  Doesn't like to admit errors that could hurt her or his Cachet as a Testifying Expert.  And somehow feels, or simply wants to feel, invulnerable.

Yet.

Somewhere along the way every Expert has taken a nick here or there.  A judge doubted her or his methodology.  Questioned the reliability of the underlying assumptions and data.  Or simply felt the other side had the better of an argument.

A Bad Expert recalls the times that she or he managed to testify despite the objections.  She or he forgets the blows that landed.  And so testifies in deposition that Nothing Bad Ever Happened in previous cases.

Beware, we tell you, of that Bad Expert.  The Bad Expert's reflexive denial opens the door to ugly questions about her or his Very Real Mistakes — and casts doubt on All the Right Things She Did in your case.

Our advice:  Question your experts closely, before you hire them, about the outcomes of Daubert challenges and their involvement in personal litigation.  Read court opinions that mention them.  Talk with lawyers who used or opposed them.  Assess whether their Warts undermine their credibility enough to choose someone else.  But, above all, make those you choose to hire admit the Bad Things they've suffered through.

Jurors may forgive an expert's loss under Daubert.  They may not care.  But they likely won't forget, or forgive, a false claim of Daubertian perfection.