One part of this I don't understand,
A lot of Americans are condemning the actions of the dive shop for allowing the guy to dive and all the other points...and how Belize has a poor standard for diver safety.
On the other hand, I see posts in other threads how dive ops in the US don't send a DM in the water and everyone is pretty much on their own. Many divers seem to resent a "babysitting" dm in the water.
How would this diver have faired in the US on a dive boat?
I'm not trolling. I have never dived in the US. Except to test a new reg once in my sister's pool...
I'm Canadian and we also don't have Dive Guides in the water. There is a captain and possibly a first mate, and their role is to get the divers to and from the dive site, and assist the divers if necessary into and out of the water. The captain of course has the final say on whether a diver will do a particular dive based on what the captain has seen leading up to the dives and the competence the diver has shown.
This independence in planning and execution produces self-reliant divers and cohesive dive teams that tend to not sign up for dives they are not qualified for or experienced to do since there is no guardian watching over them.
Those that want a DM can hire one individually or join a training dive or club/shop-led dive, which may also have qualifying measures.
When I did the Blue Hole 6 years ago, the planned depth by the shop was 130 feet. They said they would go to 130 feet, that no one should go beyond that and if anyone went deeper than 130 feet, they would not be going after them. The DM did go to 137 feet with me right beside him, and my buddy went to 150 feet briefly. My buddy told me he wanted to go to 150 feet and I said I did not want to, so the DM would become my buddy.
I did the dive on an AL 63, as I normally do, and ended with close to half a tank of air. After seeing me use about half of an AL 63 per dive all week while others ran low/out of air half way through the dives, they approved the AL 63 for me. The dive was not planned as a deco dive and we never went into or close to deco. The dive was conducted as a multi-level dive with what was essentially a long drifting safety stop at the end. The Blue Hole does not need to be a deco dive.
A brand new o/w diver who was certified a day or two before also joined our group with a personal instructor, and we overheard the arguments between instructors about letting him do the Blue Hole, but the customer got what he wanted. We were surprised about that, but have since heard of that several times.
Our Blue Hole dive was followed by two mid-range dives interspersed with long safety intervals, food and plenty of water. Again, no deco dives and multi-level dives with extended safety stops.
There are dives and dive ops/Dive Guides that are a little risky, then there are the dive ops that are way out there for what they will allow/plan for their single tank guests to do.