The point of defining hostiles is to prevent a kingdom from getting doubled. Sanc was in no way shape or form getting doubled, so whether or not 1 hit constitutes a hostile or not in this case doesn't matter.
If you want to really lock up a hostile, you make 8 hits. If you aren't prepared to do that then your answer isn't to just hit someone anyways if they hit someone else.
The game defines what a hostile is for us. We've added the cow hit being included in a hostile to prevent 2 cows from hitting 1 cow in commonly accepted practice, that's to protect one cow from being doubled up on. That was not the case here.
You can't know that someone may dodge you, balk on locking up a hostile, then wave when someone goes to dodge you.