You have to realize this is a guy who deals with the deadliest of the deadliest creatures on a daily basis. He plays with brown snakes and other extremely venomous snakes constantly. He jumps in a crocodile pen holding his 1month old son and is feeding the crocs while holding his son in his other arm. So while "deadly is deadly" it still is a relative term.
The thing is with sting rays is they don't really attack. It isn't something they do consciously its a reflex. If they can they will swim away. The most normal case with sting rays is that people step on them and as a reflex their barb whips up and goes through the person's foot. That is why I am not sure how he managed to take one to the chest, unless he completely cornered it with it at chest level and had no other means of escape. That or he laid on it.
Isn't it at the Caymans that they have sting ray alley where people go to swim with hundreds of sting rays at a time? If they were so deadly I doubt it would be such a booming business.
