If someone is diving at 120 feet pushing NDL as you said, and does not have an alternate air source, like, oh I don't know, HOW ABOUT A BUDDY, then that person is not diving safely. Would you disagree with that?
I'm amazed at how this extremely simple idea confuses people so. Buddy system, technical training that involves alternate air sources and solo diving techniques, etc....these are all foundations of dive training. Then along comes a dive shop salesman who says "you'll die if your regulator fails, better get an expensive one..." and people fall for it, over and over again.
In some ways it would be better if regulators really did fail frequently. At least that might inspire divers to actually dive safely. Instead, the type of regulator 'failure' that results in immediate loss of air is almost unheard of, so people routinely get away with all sorts of risky dive practices. I admit it, I do it too, although probably not to the extent that many do, based on what I've seen.
BTW, what do you mean by a "first stage blowout" and have you ever seen one or are you just making it up? No offense.....
---------- Post added January 8th, 2013 at 11:47 AM ----------
... the DM was clearly at fault, for abandoning his dive buddy.