Ok, check this out... Old guy I see what you mean by hard facts. Good point, there aren't enough of them. However this is a topic worth discussing. Let me explain.
Let's put our selves in a situation for a while.
You're diving on a wreck in the Bahamas or the Cayman Islands. You went in with your buddy and long time friend. You look to your right and up where he/she normally is and they aren't there. You look frantically and they are no where in sight. What do you do?
I know I was originally taught to ascend to the surface immediatly and wait for my buddy. Who, "God bless him", didn't realized or didn't care that I wasn't around and finished his dive and came back with great pictures.
My point is the diver who finds his/her self all alone should know how to properly complete a dive with out a buddy, should they get separated. This is a contingency that most people never plan for and never train for. Too many instructors bury their heads in the sand and don't properly train their students how to "safely" complete a dive without a buddy.
The whole reason I think this was is, "if I descend to 170FSW and see the port side of the Andria Doria and look around and my buddy either penentrated the wreck or went deeper, I'll be damned if I'm going to abort a dive because he/she/it ditched me."
We've been saying, "I want to dive alone." It's just as important to learn good solo-diving techniques if "you" are left alone.