Every Bundy Has a Birthday - S7-E3
Revealing mistake: At the park when Al hits the rich man, he goes down like he was knocked out. Soon after, Seven punches the kid. In the background the rich man is actually sitting up on his side and he looks at Al and Seven, then as the camera pans towards him, he lies down on his side like he is passed out again.
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