decision process...it's increasing draft status and improving earning potential long term in the NFL. If you can improve draft, get guaranteed money, and set your trajectory at 40% or more higher ANNUAL salary by coming back, that weighs much more heavily to that guy and his family than whether they are the sack leader.
Those record things become important on the back end of a players career...right now he's trying to maximize potential and I don't blame him.
His situation puts him right on the fence as to whether it would be more advantageous to come back. Hard decision to make for him, but I'd like to have that problem.