It's possible but once Dave was removed from the situation, it isn't really self-defense if the intended victim ran down the hall and the stairs to the basement to finish him. They would have passed or been near quite a few people who could help.

Ah... ( Just going to give her a reassuring smile and give her a pat on the shoulder, ) We still don't know who we're looking for so I wouldn't count you out yet.

I need you to keep doing your best, okay?