[voice]
[ Gaunt is quiet for a moment, then responds ]
We cannot hold them to a different standard. Let me tell you the tale of the destruction of Ferrozoica, which is the reason Acumen imprisoned me. Ferrozoica was a commercial hive-city on world of Verghast. It was unremarkable but for a history of trade wars with Vervunhive, another city on the same world. Such things aren't particularly noticeable as long as planetary tithes are paid, which they were.
[ A beat ]
Until the taint of Chaos came to Ferrozoica. The foul, mind bending chatter of Heritor Asphodel. It went from a productive city within the Imperium to a tainted cancer growing in a loyal planet. Every person within it was augmetically tuned to listen to the Heritor's chatter, a city-wide death cult. Everyone become a warrior, a monster. The entire population was put under arms. Eventuallym, Ferrozoica was ready to strike, and it destroyed the Northern Collective hives in an atomic strike, then laid siege to the city of Vervunhive. The Imperial guard, including my regiment, was deployed.
We destroyed them all. Every trace of them. We even burned out the hive itself, because we could not be sure that the very architecture hadn't become twisted and tainted in some way. We could not spare them, for they would continue to serve Chaos once tainted. It wasn't their fault, but we could not show them mercy or pity. Even after the Heritor himself was slain. [ Gaunt killed the daemon prince personally, but he's not the sort to brag about it. ]
So no, we must watch our civilians like everyone else, if not more so, because they aren't trained to recognize the dangers.
There is a certain aspirational ideal in being unable to kill your friends, to be sure, but that's not the reality of where I am from. Because of the Archenemy, something that can twist anyone you know into a daemon.