Way cool. 
Thanks for all of the replies all, I appreciate the input. So we had a phone version of a band meeting earlier and the bandleader backpedaled pretty hard. He agreed that it was a jerk move and will be paying us out of his pocket. He also promised that it would never happen again.
At the time of refusal he was feeling like his playing wasn't up to par that night, and was a bit tipsy. We made it clear to him that he needs to consult the band before doing anything like that again, and he agreed and appears to feel pretty bad about it.
In all, it turned out much better than I thought it would!
!