Continuity mistake: The out of order sign on the toilet changes position between shots. It's level at first. Camera cuts to other men. When it cuts back to Al it is tilted. (00:18:18)
Continuity mistake: When Al and Peg are on the couch, the ice bag changes position.
Answer: It's implied that Steve filed for divorce since in s04e16, "You Gotta Know When to Hold 'Em", Marcy says that Steve is suing for alimony. Alimony is something that has to be requested when filing for divorce. Although the show doesn't spend time on the actual legal proceedings of their divorce.
Bishop73