Devil's Trap missing scene
"Daddy, please" is what breaks John completely as he tries to fight off the demon possessing him - Dean hasn't called him that in years. "Fuck you," John hisses at the demon, who only chuckles as it continues to hurt his sons. This is what he's been worried about all this time, and he can't watch them die.
So he fights like hell to break through his possession and hopes that everything ends in this cabin. When it doesn't, he knows it'll end badly.
He still doesn't see the semi truck coming and when it does, everything goes black around him.