Saban is responsible for the trade
Saban was the one who pressured to put him on the field (most likely because he knew he was going to leave after the season)
Cameron is dumping him like he would any other Vet that does not fit his system(Mcmichael, Mare, Jeno James, Joey Harrington,Wes Welker)
There is a reason why certain QB';s cannot translate their success to a new destination. Simply they are not fit to run the current system in place. Before saban left Pep was in a system that suited him, that is no longer the case.