In Preparing and Presenting Expert Testimony, traffic engineer and accident reconstruction expert witness Lawrence Levine writes:
The conflict between the lawyer and the expert is quite obvious. The lawyer is committed to his client to do whatever he or she must, within the boundaries of the law, to win or get the best settlement for the case. When representing the plaintiff, he or she takes a great gamble that they may not receive any payment, even for expenses, should the case be lost or fail to settle before or during trial. The expert, on the other hand, gets paid by the hour or per diem for court appearance, regardless of the outcome.
For all the above reasons, it is essential for the consulting expert witness to have a Retainer Agreement which so states his fee schedule and the limitations of his involvement in the case. The attorney is asked to submit a retainer to the engineer before work is commenced to insure that this basis of understanding is documented and not misinterpreted.