Thanks for the reference, Graham.
Looking back I see "The chief said that if he had been unconscious, he'd be floating facing up & breathing close to normal." which strikes me as oddly contradictory to everything I've seen on the subject. Scuba BC's and Type1 PFDs especially are designed to *rotate* an unconcious person so they will be face-up in the water. Whether you're face up or down is just the luck of the fall, and face down just ensures a better chance of drowning AFAIK
Personally I'm not afraid of *being* in the water, but of "going" in the water--and cracking my noggin on the way. Which brings back the old question, if you recover a MOB, do you want to "drift down" on them, or come up from downwind of them. (Decisions, decisions.)