First let me express my sincere condolences to you, his family and friends.
However, let me say that I think diving deep for ".........the adrenaline and excitement of doing something so dangerous ............" is the wrong attitude to be doing such things.
Now, no offense meant, but back when I was instructing folks for such types of diving, if someone had come to me with that reasoning for wanting training I would have refused to train them. No ifs or buts, as I did so on occasion. Sure, they just got the training elsewhere, but at least my name wasn't on their C card when they had an accident or ended up dead, which some did.
Fully agree there. As a matter of fact I 'disliked' company - and the feeling of responsibility towards others at depth that I didn't even really know well at times - so much that I did almost all my deep / deepish dives solo on both OC and then CCR for the best part of 17 years. Had the same ocean buddie at times, but where he was in that same ocean I couldn't say.
Of course I hear some of you say that's just as bad of an attitude as what I point out further above, but I beg to differ and I sit here 25 years on with several dead close friends, and me still alive typing away. A good dose of 'luck' and self sufficiency is the name of the game at depth after all.