(Yes I know I'm a geek,sorry!) After reading the whole thread I couldn't help but think of a line out of a star trek episode, to paraphrase it went something like: "It is possible to make no mistakes, and still loose"
So I think the lesson here (if one takes nothing else from it) would be that there is no substiute for preparadness. It is possible to do everything exactly "right", but still have something bad happen. So always, always, always, "Be Prepared!" (yes my boy scout day's showing thru again).
I also wanted to say something about the "ICE" entry in cell phones: Here is a link too the snopes urban legends page on the ICE entry :
http://www.snopes.com/crime/prevent/icephone.asp
While a good idea, I would warn not to rely solely on an ICE entry in your cell phone, as pointed out at the above link, phone's are easily damaged/lost etc. So having the ICE entry is a good idea, but I also would recomend the dog tag idea, or in my case I purchased on of the "DAN Tags" and attached it to my BCD. Especially for dive emergancy's, I mean as a general rule of thumb there will be plenty of water around to render that cell phone unusable in seconds
P.S. Thank you again for such a great write up!