I have had several lawyers ask me to post our most recent work in the area of filing motions to strike insufficient affirmative defenses in comparative fault cases.
I have been filing these motions since 1992. A defendant has an obligation to follow Rule 8.03 of the Tennessee Rules of Civil Procedure and set forth the facts upon which a affirmative defense, including the defense of comparative fault, is based. The failure to do so should result in the defense being stricken from the answer.
A defendant has a right to have a reasonable amount of time to investigate the case and amend their answer to assert a comparative default defense of a party or non-party. This is discussed in my article called "Party Planning for Tort Lawyers" in the November 2009 edition of the Tennessee Bar Journal.