WTF... Anyone knowing how to make a proper build (which is the case of most people doing PvP) will have 95% anyway...
He can be blinded!
Victim could be a GM with GM-abused AC.
Victim could be an NPC with GM-abused AC.
Victim could be an exploiter with TB KOed AC left from unspent APs.
Victim could be behind other objects.
But really this suggestion is almost useless.