He actually left the cupboard pretty stacked at USC. In the years he's been gone the Trojans haven't ever had a losing record (closest was a 7-6 Lane Kiffin implosion) and have won double-digit games in four of the eight seasons since he left.
I'm sure he knew the NCAA was going to do something to 'SC but there's no way he could've known those idiots were going to try to destroy the program.