This is currently hotfixed and will not work anymore.
Me and a few friends tried to do AQ40, but encountered this massive problem. After a few wipes, I counted 73 bosses at once. We had over 25 tokens (500 reputation each) after just 4-5 minutes of AoE them down.
The boss spawns real bosses instead of fake mirrors, so we just kept AOE them down for massive profit and reputation gains. Not sure if it happens every time, since I havn't been able to try it.
Works as of 09/03/13.
Not sure if this counts as a guide or an exploit, feel free to move to guide if you find it more suitable.
Feel free to add any additional information if someone is able to recreate this event.