Would you know what to do?

I was out to dinner the other night with one of my girlfriends. The restaurant was filled to capacity, buzzing. The man seated right behind me suddenly fell out of his chair and went down HARD on his head. And i don't mean the chair fell over... it was still standing. He literally went out cold and down. It was one of those high chairs like a barstool but with a back. So it was a long way down. Immediately, his friends with whom he had been dining started crawling all over him, trying to get him to sit up. As rude as it was, I barked at everyone to stop trying to move him, and I yelled 'Is anyone calling 911?" I could see that someone was. But one thing became very clear to me immediately. NO ONE in this whole restaurant knew CPR, or what to do, because aside from his hysterical (and buzzed) friends, everyone just sat there. I crouched on my knees behind his head and gently held it in place. I could see his chest rise and fall so I knew that he was in fact breathing. But I knew he had hit his head hard. And the floor was cement, so I expected to see some bleeding starting to seep out from under his head. I explained to his friends that you simply don't want to move someone around who may have broken their neck, or worse. You could end up making their injury far worse. If someone has a head and/or neck injury, and you have to to perform CPR, when you do the "Airway and Breathing" part of CPR, do not tilt the head back or move the head or neck. Instead, pull the lower jaw (chin) forward to open the airway. Plus, a head injury victim can sometimes seem fine at first, but then the brain starts to swell, and you have a life or death situation on your hands. I stayed at his head and he started to regain consciousness and get really agitated. He tried to sit up and said he was fine. I calmly put my hands on his shoulders, brought him back to a lying position, and nicely said, "I know you are probably fine, but you hit your head really hard, so just do me a favor and lay here for a bit. Then the paramedics arrived (see pic above) and I backed away and let them do their thing. Net net, they thought they had him stabilized, and they sat him up and he blacked out again. It turns out he had just been diagnosed that DAY with type II diabetes. So what he had was a diabetic blackout, which is very serious. I looked over at his table and saw that he had downed a pint of beer. which is not such a great idea for someone with Type II diabetes.
Anyways, I bring all this up because there isn't always a doctor in the house... and all of us should learn some basic first aid principals if we can. I once saved a guy's life by performing a Heimlich when he had choked on a piece of steak. I was never taught how to do this, I just knew the principal and there was no one else to help him. My dad (an MD) once told me that if someone can say 'I'm choking', then they're not actually choking. But if they cannot talk, they ARE CHOKING. If you ever find yourself really choking, and there is no one jumping to your aid, you can throw yourself over the back of a chair... aiming so that the edge of the chair hits you in your gut, just under your ribs. You may save your own life this way. Here's a good site with some quick tips. http://www.healthy.net/scr/MainLinks.asp?Id=170