A high risk does not mean it is a matter of time so let's say "IF" he is killed.
I have visited him in Thailand and he has direct connections with the government reptile center in Bangkok so if something unfortunate happens to him, the animals go there, which is a better contingency plan compared to what most people have. He also has access to all the antivenom he needs through the same place, which is relatively close to his home.
Look, I do not agree with what he does but Chris is not your crazy rattlesnake pastor, he understands what he is doing and understands all the risks associated with what he is doing.