In this particular incident, I think both points that are being made apply. At the end of the day, nobody was seriously injured and that was probably evident from afar after a couple minutes had passed. Also, with the other guy's boat still being under power, there wouldn't have appeared to be the need for a tow.
To many other people's point, there were 8-10 boats and most of them had more than one person in the boat with them, not one person (outside of a guy in a canoe) pulled anchor and idled over in our general area and offered an; "Is everybody ok?". Plenty of them were willing to pull out their phones and record the aftermath though.
I appreciate all of the comments on this post. It was meant to just get some clarity on the legality of the situation (which it did). But, it has turned into a helpful discussion and many people are bringing up good points as to what to look out for and how to safely render aid in the event of an open water accident. Again, thanks for the information and commentary fellas.