This is a great story for a couple of reasons, I think. One is to point out that practicing skills like regulator exchange is well worth while. It's one of those simple things you can do while you are swimming along, and staying facile with it can prevent a minor annoyance like losing your reg turning into a major problem like a runaway ascent.
Another is to point out, again, the importance of having protocols in place for things like buddy separation, and STICKING TO THEM. I've had a couple of buddy separation events. One occurred shortly after descent from a boat, in about thirty feet of water, in pretty poor visibility. I was buddied with my husband, and we were to follow another buddy pair. I lost everybody moments after descent -- looked away very briefly, looked back and they were gone. When I couldn't see lights or bubbles in a short time, I ascended. The boat captain was calling to me, trying to point out the bubbles, but frankly, I thought that if I had lost these guys when we were all in the same place, doing the same thing, the likelihood of finding them if I just tried to descend where I thought they were was pretty low. I stayed on the surface for several minutes, and eventually my husband surfaced and we regrouped.
In another incident, I was practicing mask removal and replacement in shallow water and lost buoyancy during the drill. I had my mask off and began to go feet up to the surface, but without my mask, I wasn't sure what was happening, and before I could get things sorted out, I was on the surface (this was from about 20 feet of water). I did not see my buddy or his bubbles, so I waited for him to come up. He decided to deploy an SMB to let me know where he was, but he didn't fill it well enough, and it didn't stand up on the surface, and I didn't see it. The time it took to deploy the SMB was well over the recommended one minute. I was actually beginning to get quite worried about him by the time he surfaced, but again, searching for somebody in our local visibility is really not a very rewarding activity, especially if the person for whom you are looking is moving around as well.
In Rick's story, the original ascent was avoidable with better skills, but the subsequent anxiety/apprehension was totally avoidable simply by following protocol.