This also raises some questions about dive planning for these sorts of dives. One of the nice things about the system in which I was trained, is that everybody is using the same methods of determining decompression, so there is rarely any need to discuss the profile beyond agreeing on the max depth and bottom time. But if you are diving with a buddy who is using a different method of computing his profile (whether that's different laptop software, or a different computer) would it not be a good idea to agree, beforehand, that you will do the decompression requested by the more conservative (eg. longer deco) method? I guess I have a hard time understanding why someone would terminate his own deco and surface, leaving his buddy (with whom he apparently executed and almost completed the dive) to finish his time.
There was a very nasty accident in California a few years back, a double fatality, in which a tech diver aborted his deco to rescue a recreational diver who was out of gas, and left his buddy doing what appeared to be uneventful deco at 70 feet. The recreational diver died, and the buddy left at 70 never surfaced. To my knowledge, to this day, no one knows what happened to cause his death.
One certainly doesn't know if a buddy could have intervened successfully in any of these cases. Denton Byers had an attentive and highly capable buddy, and died anyway. But without a buddy and a tale to recount, none of the friends or family know anything about what happened, and I can't help but think that they would forever wonder if the outcome would have been different, had the diver not been alone.
