Nooooooo, please read the previous posts, I hadn't attacked anything since I started my walk from Hjallmarch, they attacked the guards as well. They just went wild.
I did read them, doesn't have to be your arrow, throw one into a crowd and an NPC will just attack the next, then others pick sides, guards get involved and so on. Arrow is the easiest way to get it but any kind of attack even an NPC knocking a bowl into another could work. Or even more likely a bandit strolled by an NPC attacks them but hits the other, it gets taken inside town and so on. You stroll into it and svcks to be you.