Either something was so bad in terms of personnel, actions, employment or performance that he had to go. Like as in, go, anyone but you is better. We will figure it out. Bye.
Or 2. Someone came available and USC felt they had to go get him. And it was a significant upgrade. Either a hot up and comer who knows how to mask steroids or an established respected dude looking for a change. Maybe Rob Ryan knows someone from the NFL.
You don't hear that much about NFL weight rooms or training programs. Why is that? Do pro players all have their own personal trainers?
On another note. Years ago, weirdly. A lot of the staff. Assistants and strength and trainers. All had their contracts expire about now. I always thought it was weird. Spring? Mid spring? Like April 15 or May 1. Maybe it was an academic year thing. So perhaps his contract was coming to an end and this was the time to do it.
Don't the Trojans start summer workouts June 1? If they do it's my understanding that the S&C Coach runs those which if true means USC needs to find a replacement fairly quickly which lends to your theory that USC has someone in mind