Read the whole thread thus far a few things to say.

People are more apt to respond positivly to advice delivered in a professional manner

My general rule with keeping snakes is "you will get bit"

I think starting with a hatchling would be much better but he probably knows this by now

Lastly, "Instantly the boa bites his face" Im watching this video and could tell the boa was tracking the foolish keeper for a good 6 seconds and knew he was going to be bit 6 whole seconds before it happened. two things to always watch for, especially when others are around, is tracking behaviour and S shapped necks.