This is not exactly a bug report, rather I’m describing a useful feature (that probably wasn’t intended) that I’d rather not see someone label a bug and remove.
When a survivor with a passive counterattack is performing an extended action, counterattacks are not disabled. As a result, one of the attacking zombies will get slapped each turn. This results in a lot of “zombie attacks you, stop? y/n”, but far less than tanking hits for the entire extended action would.
This isn’t really exploitable to gain an advantage, but it is very convenient, as it allows performing long extended actions relatively unmolested by zombies too weak to pose even a semblance of danger (dodges are disabled during extended actions, so dangerous zombies get even more dangerous).
In fact this “auto-fight” method is so convenient, I often butcher corpses just to start an extended action, so that zombies pile up and form neat corpse piles rather than forcing me to chase them around while they stumble due to constant stunning and knockbacks.