I tested the proc multiple times yesterday and it has absolutely no use in PvP other than adding damage to the player. It doesn't stun and it certainly doesn't do any damage. What you are talking about isn't the proc killing you, it is the axe bleed skill mastery.

I think this is either a nerf which happened because of the dps crying so much or it was a mistake.

Someone please look into it because making a proc useless in PvP hasn't been done to any other weapon. It should be the same for the sword.