I just played this game for the first time ever, today. Everything was going well until it was time to escape from the vault. I ran into Butch and his mother was trapped with the Radroaches. I was going to help her but I couldn't figure out how. Meanwhile the quest info said that I should go back to my desk and get my things, which I did. When I walked up to Butch again he said his mother had died and I could have helped her and it was my fault. He vowed revenge or something. I didn't know what to do... so I shot him.
Sorry Butch, but as Elim Garak once said, "Always burn your bridges behind you. You never know who might be trying to follow."
Picked up my first bit of bad karma with that. Not sure what to make of it.