Earlier quoted context omitted.
His life was most definitely in danger.
There seems to be missing something in your story to show danger. They just asked for his cash, nothing show any sign in danger in that. Would you pull out a gun because someone asked you for food too? Was there a threat? Which kind of threat? Did it look like these guys had the means to carry that threat and did it look like they actually were going to carry that threat? I wouldn't kill a guy in hope to get a few th…
It changes if they come up and demand money.
Losing a couple thousand bucks would suck, and if that was guaranteed to be the end of it then I'd rather that be the end of it. The problem is you are dealing with people who are already willing to commit robbery, there is any number of ways that situation could get violent. Once it does then who knows what happens.