[ You’re right. If the possum actually attacked anything, it was more than likely rabid. ]
Opossums have a very low body temperature which makes them practically immune to rabies, though it can happen and this could be a very rare case...
LOL! I actually saw (and researched) that after my post, and it appears you're correct.
Anytime an animal acts out of character, though, there's usually a reason....snakebite, parasites and illness, among others.
Also, we only have the man's word it WAS attacking his dogs. It may have just been in his yard and the dogs were raising hell over it. I know mine do.
Be that as it may, getting arrested for dispatching a pest with whatever means is at your disposal is just totally ridiculous, IMHO.