I never said anything about privacy. I've had plenty of insta-buddies and we sit down and talk before the dive so we both understand what's going to happen. If I get a bunch of attitude or the feeling that I can't trust them to tell me the truth then I just dive solo. Really now, would you trust someone to save you in an emergency if you DIDN'T trust them to give you an accurate gauge reading?
Not off of me he wouldn't. And not off of any diver I'd want to be with. If someone is so distract that they a) Can't hear another reg 18 inches away, b) Can't feel someone unclippping their crap, and c) Can't feel the bouancy difference when their deco bottle goes away then they really do not belong in the water.
The rules need to suit the situation. In an easy, clear-water drift dive in Cozumel, anything over 1000PSI I just want an "OK" signal. Overhead, deep, wreck, etc requires different rules and conventions. I think we can all agree on that.
I'm also quite sure that any of us would do whatever we could do to help a distressed diver, buddy or otherwise. There are plenty of ways someone could go OOA and not all of them involve lies. Being mentally prepared for the situation goes a long way towards a favorable outcome.
-Charles