Many on this site have fed live mice. Why aren't you complaining about that? They are bit with hundreds of sharp teeth, then constricted so hard that they suffocate.

Is that not suffering?

Also, what did you want that guy to do? Yank the chick out of the snakes mouth? He could risk getting bit, which would bring worst news to our hobby.
I'm pretty sure he wasn't expecting the snake to eat the chick that way.