Crime system reporting broke, impossible rep drops
Confirmed on a new game and by some others on reddit.
When killing the executioner at Rattay, you will receive a reputation drop with his Rattay sub-faction. This is despite his home is isolated and no-one is around with in any realistic sight or hearing radius.
This is happening for most if not all NPCs as some how their factions knows instantly you have wronged them. So unless his animals are reporting you as you kill him, something is definitely broke and triggering when it should not.