The hoax theory doesn't jive with the type of person Ben was, as attested by his family and friends. If he had a history of dishonesty, very few friends, shady deals, etc., then there might be cause to speculate.
Now, if someone was a shady character, they might pull off a hoax like this:
A person plans a deep penetration dive in Vortex cave and stages bottles, posts the dive plan on Facebook, and then attemps to do the dive but cuts it short for an unspecified reason, he might not have any deco obligation and could simply ascend and exit the water. Maybe he intends to go back later, so the staged bottles are left in place and the gate is left open.
He unlocks the door to his car, checks his cell phone and gets a message that rocks his world. As he is standing there alone in the parking lot at night, it occurs to him that all he has to do is take the gear he was wearing and walk away. Just disappear. Everything is in place for people to assume that he perished.
He didn't plan anything. Just spontaneously came up with the idea and walks away. He could hide his gear somewhere, steal a car, go back and get the gear and disappear.
Not actually planning a hoax, in this case, could work out better than the most diabolically engineered scheme, because he truly didn't miss a thing.
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Alas, that would make an incredible story, and I believe that the tiny possibility of that scenario is partially what has kept us all glued to this thread.
The other riveting factors are the brash disregard for training, safety, authority, establishment, loved ones, etc. The dichotomy between the skilled "cave diver" image that was presented to his friends and family and the polar opposite image exhibited when evaluated by those who are actually trained and experienced.
The fact that he is still missing in a relatively simple cave system and small dive park gets the collective imagination spinning.
Hints from various posts that' "there is more to the story", and "key info will come out later," begs for speculation.
A request for more divers to continue searching adds a gut-wrenching possibility that a glory seaker will get himself into trouble and the cave will claim another victim.
I lost my best friend in a bizarre accident when I was 30. It was his own fault and it shouldn't ever have happened.
At the time, I would have come up with any scenario on earth to grasp on to the tiniest possibility that he was still alive. But alas, bad things do happen to good people. Especially when they push limits too far and make poor decisions. This is what happened to my best friend 18 years ago and what happened to Ben McDaniel last week.