Game Mechanics: double attack when i dont have the skill

[Varren]

I've noticed that I'll sometimes double attack, when I don't even have the skill yet. I think its just with 2 handed weapons, but that's pretty much all I'm using right now, so I might just have not seen it with the 1hers. Also, I seem to notice it most on killshots (the last hit of a fight). I have also noticed mobs doublehitting me to kill me, when they werent double attacking previously in the fight.

Lucas