If Jamie is the one who ordered the hit on his family i don't blame him
Beth has treated him like total shit, constantly bullies him and threatens him and psychologically torments him. And John can't even bring himself to say he loves him as much as his other kids despite Jamie saving his ass legally multiple times and being 100% dedicated to the family.
They treat Jamie like an outcast, honestly i don't blame him if it was him who did it, i'd kind of grow some respect for him actually.