Lol Mitsy, I'm guilty of committing a similar crime-- wiping out a nest from the top of our AC, but I never killed the birds. I made sure I let them fly first. I don' t think I could kill something that big, anyway. Plus, I wouldn't kill an insect/animal that can't harm me, such as a bird. Now Lizards, they can be a bit tricky.
This one time, I was sleeping and my window was open. A bird flew in, and was chirping around the room, and my fan was on. It ran into the fan and the blade killed it :( I had a proper burial for the bird.
Why don't you get your neighbour a shirt that reads: Sparrow Killer??!?!