Currently working -
A warlock can enter an arena - life tap / hellfire their way to death...
Start running over to the other side and see who you are fighting, while during all of this a healer is rezing them. They can identify the other team, take the rez, and then proceed to be buffed and healed.
A huge exploit? No. But it can allow you to preform strategies against teams and rush in, giving you the edge.