@Mrs T
I agree with you. The unfortunate outcome of all of this will likely be that the district will have even more trouble recruiting bus drivers. It would appear this driver was only following instructions and policy. But for that they get chased down by out-of-control parents that hadn't a clue what was going on and could have potentially endangered all the children on the bus by instructing them to get off.
I know if I had even the slightest interest in being a school bus driver I certainly wouldn't do so now. Especially knowing if a kid misbehaved, I'd find myself in more trouble than they.