After reading the posts on this tragic event, all I have to say is this. The diver had a MASSIVE heart attack, in that case it doesn't matter if your on the surface or under water, your basicly going to be a vegatable if you live through it. You wouldn't have been able to survive this event, unless you were standing by with a AED and someone doing CPR withing the first minutes or so anyhow, With the diver still holding onto his light, this shows it was so quick, that his body didn't even have time to flinch.
Why does it matter how quickly someone responded.
The fact that this was a already certified diver, makes no concern about wether or not he was able to dive. Diver will dive despite what others say, they will pass the limits set forth in training just to dive. Basic OW divers are only supposed to dive to around 60' anyhow, he made it to 80 something, although he was with a instructor as a group, He was removed from proceding any further in training, but was not told he could not dive, he joined the group anyhow. this is not the fault of the instructor, or anyone involved. He was a diver and wanted to dive.
The instructor ascended performed his lost buddy check sent two other divers down to look while he waited on the surface. He probably did notify people on the surface that he had a lost diver/buddy but until that time passed from the other divers coming back, you have to wait. Most rescues in this type of event don't happen right away, it takes some time for everyone to get their act together, enter the water and perform the search.
Let this tragic event pass, and give the family and those involved some peace before bombarding them with what if's, could have's and should have.
My condolensces to the family and to those involved. its not easy seeing someone pass much less trying to perform cpr to bring them back and not succeed.
Its not easy being the person on the giving end and watching somone suffer to only pass a few minutes or hours later. I have been there and I know most people have never seen or been there, diving or not this was a tragic event, and NOTHING anyone could have done to prevent it.