And if one or more students had killed the idiot teacher they would have to live with that, after finding out later that it was a "joke," for the rest of their lives. Not their fault but you can bet it would haunt them.
Yes, he put people's lives and limbs in danger.
None of the what-if’s you described actually happened so the ‘possibilities’ and ‘could haves’ are irrelevant unless you are somehow advocating for tighter fake-gun control laws so situations like this don’t happen again. Also, your impassioned emotional rant is more indicative of leftist/liberal group-think than logic and reason.
All we know from this case is that a teacher fired a harmless blank gun at young adults in order to scare them or drive some point across. While he acted in poor judgment and should face some sort of reprimand or dismissal from his school district, he committed no actual crime as far as we can tell. The media outlet that covered this case neglected to specify the details (as usual), which led many people to be duped into propagating memes that don’t actually exist.
All I’m trying to do here is help people to NOT be tools.