I'm not sure about the details of that incident. But like I said earlier I think a lot of people underestimate how powerful the larger constrictors are. It's pretty hard to grasp until you've experienced it. In my case with my Burm it was when we had to restrain him to do a tracheal wash. It took around four people to restrain him. This snake is around 10' 45-50lbs (not a massive animal) and it was extremely difficult. I think that once a snake reaches a certain size, There really isn't much that you're able to do by yourself if you're caught in the wrong situation.

I think it'd be very highly unlikely to be killed by a Boa Constrictor, having said that, you can essentially eliminate all risk by having another person around with larger animals.