I agree that complacency can be a major issue perhaps more in experienced diver or new divers that are overconfident particularly when combined with panic . A few years ago there was a fatality on the Islander Wreck in the Saint Lawrence at the town of Alexandria Bay. The islander is a popular training site drawing folks from Syracuse and beyond. It starts in about 25 to 30 feet of water and is about 40 feet at the deepest point. It is a wooden wreck about 100’ long and well preserved due to the fresh water environment. It sits parallel to shore and about 50’ out from the entry stairs provided by the town for divers.
A diver from, I believe Pennsylvania, was attempting to excavate under the wreck if memory serves with a propulsion unit pushed under the wreck backwards. He had been asked to stop since instructors were there with classes and the vis was ruined by the sediment. He was also diving solo. His body was discovered later that day as the water cleared. He had become stuck partially under the wreck apparently when his buoyancy changed as his air supply was used at which point his BC snagged on the underside of the wreck. The person who recovered the body only had to push down to free it from the wreck. I do not know what certs he had but had heard he was an experienced diver but apparently once snagged he most likely panicked and consumed the last of his air in terror. I suspect that if he had not panicked he could have removed his BC and backed out of his eventual tomb.