Personally, my take on this situation is firstly that I never ride anywhere without both a spare tube and a patch kit. Secondly, if I see someone off their bike up ahead, the first thing I do is slow down to see what's going on, and if they need some help them help them. If they're waving their arms at me, I'll plan to stop. They either need help or are trying to warn me about something. Thirdly, if someone was down with two flats, I'd offer them the use of my patch kit and pump, or offer to fix the tire for them. I don't know what the dude expected to do by putting a second cartridge of CO2 into his tire if the first one didn't work. Don't know why he'd attempt to reinflate his tires anyway knowing that if your tire (or both of them) suddenly go flat, it's because there's now a hole in the tube and they need patched or replaced. So that, combined with the fact that the guy didn't even have a patch kit or spare tube, leads me to think that he wouldn't have known what to do with one if he did have them. Given his attitude, I can't feel too sorry for the guy.