I'd like to take this is a bit different direction--the fact that contact was lost with the victim diver during the dive. We have been concentrating on the rebreather itself, and not on all the other aspects of this accident. The lost contact kept assistance from occurring in a timely manner, as described at the very beginning of this thread. In accident analysis, all aspects must be examined, so what about the lost contact?
Years ago, when I was diving in limited visibility with my buddy off the Oregon coast, we used a "buddy line" to keep us together. The buddy line was a four-foot ,1/4 inch diameter nylon line, with brass snap links on the end and attached to a belt harness which had parachute "D" rings sewn into each side of the belt. That led to my buddy and I being together and not separated when we were rolled by a very large wave. We ended up on the surface together after being rolled, dumped our weight belts, and spent about 3 hours awaiting pickup by the U.S. Coast Guard.
What would have been the outcome had these divers been linked together with buddy lines in that limited visibility? Would this have been a fatality, or simply an incident because they had constant communication with each other and could thereby assist one another when the emergency occurred with the rebreather?
SeaRat
That's an interesting question. I don't think buddy lines will ever be an accepted best practice in the recreational realm, however I completely understand the desirability of the system in the commercial and military realm...