I think you would have to consider the number of people on the boat and the severity of the initial victim. If the buddy gives the OK at the surface, I can hardly find fault for the crew being 100% focused on getting a victim who passes out stabilized and on oxygen for a 2-3 minute period.
If you have a bunch of (extra) people on board you could throw a line to the other diver on the surface, set a watch or maybe even put a swimmer in if you got nervous about the situation, say they arrived on the surface too soon, or too late.. etc.
But a diver could sink in a few moments and would be invisible and unrescuable within 15-20 seconds of inattention. Even when conditions are calm, a lot can happen really fast on a boat in the ocean,
I would need to see a ton of negative information before I would be allocating any blame toward the boat driver and crew.
I am surprised he was found so close to the dive site, after this long of a time. Based simply on this observation, it makes me wonder if the technical cave diving community is much, much better organized in handling missing diver situations than the local technical divers.
With scooters, clear water and the ability to conduct a search well off the bottom, it presents less challenges than some of these deep caves, although there is probably a much larger search area.
