With all due respect you have that wrong. I just listened to the full PC. What Whaley said was that he, Rex and Terry were on their post game conference call, Rex asked to speak to Terry alone. After that meeting between Rex and Terry, Whaley was informed that Rex was no longer the coach.
We can speculate as to what transpired, but it seems pretty obvious. Terry Pegula saw what we saw on the field, the difference is it's his team and his money. Whaley didn't need to ask why, he knew as well as we all did.