My wife posted on the YouTube comments the following :
Hi Jim! Yes... That's definitely a Sand Tiger shark. Not sure why it's mouth is so deformed. But, what I am sure of is that shark was completely asleep when that video was shot. I was a volunteer diver at an aquarium for 8 years and it was very common for sand tigers to circle slowly like that over divers when they were asleep. Another indication of that is the gaping of it's mouth. When sharks sleep, they swim very slowly and gape their mouths. The shark is gaping is mouth and literally "gasping for breath" trying to keep itself oxygenated enough since it's not swimming fast enough to push enough water across it's gills to keep oxygenated. The shark is in a "semi conscious" state, basically kind of like sleep walking.
This is just my own personal theory, but I think our exhalations attract them somehow while they are sleeping. I did "dive shows" regularly at the aquarium while scuba diving with a communication mask on. And there would be a live audience that I would interact with and answer their questions about the sharks, conservation, etc. It was very common to see sharks sleeping and behaving in this manner and they would oftentimes hover over us why diving when they were sleeping.
At no time were the divers actually in any danger of being "eaten alive"... It's a very harmless encounter.