Did not bot on main account but did on another account WHILE I was playing on main.

So blizzard can accurately tell which account it botting, not just whether HB is running in the background while a wow process is open. I think they are using heatmaps of some sort to catch potential botters. I did not profit off of the bot on my main account at all and it didn't get banned, not sure if this is one of the false negatives that blizzard leaves in to trick people, but I actively avoided ever launching HB while my main account was the only wow process open.

 

They likely can tell when you attach to the process.

think of it like cheatengine and Vac on steam

 

Correct, but I still wouldn't risk it in case they ever change that policy.