Sorry for your loss Anna. It takes a pretty level head to not lash back, but if it truely is an accident then I think your doing the right thing. Our society is too litigious these days anyways. I think if you can find out who the owners are, it wouldn't be out of bounds to ask if they are willing to replace your birds that were lost. Decent people will usually make a gesture to set things right. Hope the last one makes it.
It turned out that I know the AC guy, so I might ask them to repay the vet bills (unofficially). One of the missing girls showed up just missing her tail, so I'm holding out hope that the other two are just hiding, and the one in the pic is the worst I'm facing.