No maphack
Before you get all grumpy and stuff, let me explain you , with my own words :
if you clicked on something ( barracks / towers ) or someone ( heroes ), and you don't change your cursor position, let's take the weirdest argument : until the game is finished, the red circle will never disappear, since your last click was on him/it/her.
You can always try yourself, you'll see what I mean, and you won't call yourself a maphacker right ?
Red circle starts when you have the vision of a heros, given by creeps, or allies towers/barracks/heroes near him.Doesn't go off until you click/aim on something else.
And of course, the famous host pick/repick/swap/revive bug.
Later, hope I helped.