The person who passed out came back to consciousness and nothing more actually happened... thank goodness. In fact, I don't think 911 ever got called.
When it happened, I asked my friend if he was certified in First Aid and CPR. I was certified all through college, but I haven't been since. He said the same, that his certification had lapsed, as well.
Still, I'd take the chance to save someone's life though the Good Samaritan's Law wouldn't apply to me. I'd rather try and fail than do nothing at all.
I was surprised at how many people just sat there and did nothing. No one ran to assist. Everyone was googly-eyed just waiting to see what would happen. They always teach you in First Aid training that people always assume that someone else is going to call 911, so you should go ahead and do it. If you duplicate a call, then at least you know it's being handled.