I have seen a case where a guy didn't feed his bp often enough or something that was big enough and it struck at everything that moved. if you went to pick it up or do any maintenance its stricking but once he started feeding it properly it stopped. not saying its the case with this one. but it can happen.

I've also found that some snakes just take more persistence with handling. you have let them bite you over and over, and eventually they get used to the handling and stop. i've had snakes that started out as constant biters but with persistence became some of my most docile snakes.