Moral of the story is to do a quick mock air share, including deploying and breathing off both regs, every time you don your gear. You don't want to wait until your buddy is actually OOA at depth under a shipping channel to realize that you can't effectively get a regulator into his mouth.
I'm quoting myself here for all the people who are so bent out of shape about the thread title.
Frankly if someone can't read the OP and figure out what the point was, then nothing I could have said would have saved them from themselves anyway.