Here is a recap from my perspective. I'm sharing this as I think it benefits everyone to know as much as possible and learn from every incident so we can all help prevent future injuries and deaths.
As I mentioned, there were 10 divers and 2 dive leaders on the boat, plus a mate and captain. 5 divers going on the deep dive (including me, my wife, 2 other divers we had already dived with during the week and the now deceased diver who was on his first dive with us). The dive leader for our group is an instructor, but he was working as a dive master on this dive.
A complete dive briefing was given, including dive details, safety, hand signal and recall procedures. The dive was planned and executed as a drift dive while the boat moved to a shallower area of the reef for the second group of divers. Our dive was to a max depth of about 110' (varied slightly between the group), all divers on air. We did an uneventful descent to about 100', moved across the reef to about 110', then turned and started our ascent at the 14 minute mark. I was mostly looking for photo opps and watching for my wife. The two of us ascended gradually to about 75' as we returned towards our entry point. I then noticed a diver a good bit above us and the dive leader signaling him to descend back to the group. When that diver did not react to the signal, I observed the dive leader ascend to him. grab his BCD, ask if he was OK and grab and look at the divers SPG. The diver appeared to be breathing at that point.
As my wife and I continued up to our safety stop the dive leader ascended to the surface with the apparently struggling diver. My wife and I completed our safety stop and at that point I noticed one of the other divers signaling to us to surface. When I reached the surface, the diver who signaled to us yelled "Help, he's unconscious". I immediately inflated my SMB, extended it into the air and waved it to signal for help while the dive leader and another diver supported the unconscious diver to keep his head above water. There was some chop and it took a few seconds until I spotted the dive boat making it's way to us. The boat was back to us in under 5 minutes and maneuvered directly to the unconscious diver. A civilian yacht was closer but continued past us with no pause. When the dive boat returned they threw out the tag line and then immediately worked to get the diver into the boat. I was furthest from the boat and boarded last, immediately removed my gear and joined the dive leader and diver who called for help in performing CPR. There was no pulse at that point - we continued taking turns providing chest compressions and supplying O2 while continuously clearing his airway of fluid. We confirmed a "pulse" while doing compressions, but otherwise no pulse was present.
The boat returned to retrieve the other divers, with the mate telling my wife there were no other boats available to get them.
Roughly 25 minutes from when I surfaced, we had the 2nd group on the boat. One of them announced he was a doctor and joined us doing CPR. We continued CPR to the dock and another 5+ minutes until the ambulance arrived. We changed out the O2 cylinder for a 2nd one en-route. When EMS arrived, it took them several minutes to get on board. They set up an AED but no pulse was detected while I was in hearing range. He never regained consciousness.
I was told post dive that the now deceased diver had poor buoyancy control throughout the dive, and that someone overheard him say prior to the dive it had been a number of years since his last dive but that he was a dive master. If true, he probably should not have been on our dive, or even on the boat prior to doing a refresher. Beyond that, the dive leader, crew and other capable divers all responded well, even "heroically" if you will, given CPR was performed for almost an hour. The dive leader and one of the other divers skipped their safety stops to respond and the other diver stated his DC wanted a couple minutes of deco. I believe it would be fair to question the decision to retrieve the other divers, but given the sea conditions and wind I believe that it was within reason to not risk any further divers.
If I was running things, I would have suspended diving the next day to do a thorough review with all hands to discuss the circumstances, decisions and allow all others associated with the shop and water sports team to take part. I would also provide time off to the involved staff to process and grieve. As I mentioned in another forum - while there was one fatality, it's fair to say their were multiple "victims", as every diver on that boat and all crew were impacted, if not traumatized, by the events.
To C3Diver - Showing up and interrogating the crew about the previous days events was a poor decision in my opinion. I would not expect the crew to share any details or speculations beyond the fact of the fatality. If a fatality the previous day created doubt, it was your right to cancel. Telling others what you knew to be factual is a judgement call on your part and I understand it, but being an instructor and having led many dives, I would never discuss details of an incident while an investigation was certainly ongoing.