At the end of the day you really can't measure bf% with all that much accuracy, and that's especially true for low bf%. At low bf%s, the error margins of the test get closer and closer to the underlying measurement itself, thereby making the results of the test less and less meaningful. There's no real way of knowing that the guy in that photo is 6% as opposed to 4% or even 3%. So it's misguided to use the fact that the guy in that pic looks like a corpse to say that 5-6% is close to death.

with 100% certainty I can tell you he's well over 9%.

I don't mean to sound combative, but you can't. The tests -- even the one where you send samples to a lab to get your water% -- are not accurate enough to support that statement, and you said yourself that everyone carries weight differently.