I suspect that his diving quals may have been exaggerated by a bit. If he was already a certified Master Diver (50 dives), I don't know of any additional diving quals that someone could get so quickly, let alone 2. As a certified Master Diver, the next step would have been pursuing his DiveMaster cert, which would have required at least 10 more dives and a lot of time & training.
I think he very likely rushed his ocean dives before he was ready and got himself killed, perhaps even a heart attack.