Happened at machine shop prestige mission. Basically brought the wrong stuff and was left with 2 menders and 1 battlepod.
After killing both once (and they revived each other in between) I spent the next few minutes slowly killing them.

One died. And left a body. Again. Promptly revived.

Maybe I haven't been the clockworks long enough to study them, but as far as I know Gremlin Twackers don't leave any bodies after their second deaths. Unless that's broken too.