KC, some people have hundreds of dives on an OWD ticket. Some places require certain levels to ensure the diver has been "trained" to dive to a certain depth, but most likely if anything happens, PADI will help defend them if the diver qualifications are met.
Operators sometimes require specific certifications, and presumably have various reasons for doing so... insurance perhaps, or just wanting to be assured of their divers meeting a minimum standard of some sort.
In these parts, "solo diving" is widely practiced (with full redundancy etc.) but I only obtained a solo card as I approached my 5000th logged dive... and it was strictly to meet the requirements of a liveaboard operator. I didn't expect Mrs. Stoo to want to do five dives a day. So "technically", had I had perished, I would have correctly been referred to as a "newly certified Solo Diver", when in fact I had logged 2500 solo dives many of which were multi-stage decompression dives, in freezing cold water.
Certifications often mean "squat". It's the logbook that matters...
Regardless, this is a very sad situation and my condolences go out to his family and friends...