It's one of the more rare PvP desyncs.
Basically desyncs can be classified as:
Player vs. Player vs. CPU (Time-out Desync)
Player vs. Player vs. Player
Player vs. Self
Time out happens the most, and the other 2 are server glitches. they only happen once in a while, but they are incredibly difficult to fix.
Zanz should be aware of this, but as far as I know, he hasn't been able to figure out a solution to the problem.