Nope, the punishment was death. It wasn’t done until it was done. If they couldn’t find a vein, they should have found a rifle or a rope.
Well, regardless, his crime was already punished twice actually. Once 2000 years ago on the body of Jesus Christ and secondly in the botched attempt to kill him. Both are punishments for his crime the second one being unjust, but it was still a punishment. A second attempt would also be unjust.