Collateral estoppel is a doctrine that allows a court to bar relitigation of an issue that was already decided in a prior case. This case, Hexum v. Parker and Parker & Halliday, 2017 IL App (3d) 150514-U, is unpublished. The decision is one of many that reject a collateral estoppel defense to a legal malpractice action.
Hexum sued his lawyers for legal malpractice for allegedly giving him negligent advice in his divorce case; specifically as to the amount of maintenance he would owe.
In the underlying divorce case, Hexum entered into an agreement with his ex-wife to pay her $6250 per month and 35% of any bonus or stock option that he exercised.