I've had an alien go mad and kill one other alien I think, but that's the only other alien there was in that vicinity. I've also had one kill his buddy who was near my troops, but that was cos his aim was rubbish I think
(Plasma pistol ain't too accurate).
I've noticed that when the aliens cower in my campaign they sometimes appear to 'drop' their weapon on the floor (you can see a plasma rifle on the floor for instance) while they are cowering, but then the next turn when they recover, they suddly have their weapon again
(though it makes a bit more gameplay sense to me that cowering aliens/soldiers would keep their weapons, I remember in a much earlier version when soldiers freaked out much easier, they would drop their weapons and run about, and that became really frustrating to recover from)
Incidentally, I've never seen one of my troops freak out yet, though I don't loose that many troops...
(and they tend to die way before they lose morale)
Civilians attacking you is part of the story. It's this XVI virus and you can research it to get the message, that aliens use humans.
Also, I often got the message "alien bla is in mad rage", though in 2.3 I had more aliens gunning down their own kind than in 2.4.
Ahh that's interesting, that means the electrolaser makes much more sense, I understand why its a primary weapon now even though its a stungun...