He mentioned it to Catherine in the 802 ep "A La Cart"GrissomFREAK said: OK I must have slept through an episode -never happened to me before not even once, because until last night, I didn't know that Warrick was getting a divorce
Warrick: One minute we're married, and the next ...
Catherine: You know what? Good for you. Divorces should be like Band-Aids, one quick yank and done.