3.1.3. Rebuttal Experts.Contract review appraisers may be engaged as rebuttal experts in litigation. Rebuttal is a legal term meaning evidence introduced by a party to meet new facts brought out in the opponent’s case in chief.149 Its function is to “explain, repel, counteract or disprove evidence of the adverse party.”150 

Rebuttal experts are typically engaged by the Department of Justice in condemnation trial proceedings to contradict or rebut the analysis and conclusions of another appraiser. As a rebuttal expert, a review appraiser may be asked to review an entire appraisal report or to focus on a specific element of an appraisal (for example, the quality and reasonableness of the highest and best use conclusion or a specific approach to value employed). 

Review appraisers who prepare rebuttal reports for federal litigation purposes must comply with USPAP and the Federal Rules of Civil Procedure, particularly Rule 26(a)(2) regarding expert reports.151 As with all assignments, review appraisers must never allow the assignment conditions or a client’s objectives to cause the results of a rebuttal assignment to be biased or not credible.152