Hmm. Strange. I am unsure what this could entail then. That's what SHOULD happen to Kerfur, in theory, but mine always got destroyed by the EMP orb. By any chance, do you have prop impact physics on? At least, I think that's what it's called.
Hmm. I'm unsure then, being honest. He shouldn't operate on battery anymore, to my knowledge, so if it's not the EMP orbs, it might be an event for Kerfur specifically.
Hmm. I noticed it starting to happen when the cyborg boars came out to play for the first time. Though, if that were the case, I feel like they'd just destroy Kerfur flatout.