I believe the video is legitimate, and the Blue Hole, as someone said before, is a site that has killed more than 100 divers over the years. This is a deep dive site, but for someone on full tech gear, it isn't a problem – think the deepest part of the bottom is 120-130m or something in that region – but many try to bounce it on single air cylinders, hence the fatalities. I think the guy in the video was trying to bounce it on air, hence the reason he was showing his computer to the video, then just was too narked to sort himself out and head back up.
I have seen another video taken by a tech team and they film a body lying on the bottom in recreational gear.
There is an archway from the Blue Hole to the open ocean, and the top of the archway is a good 56m. It is also wider than many think it is. It is common for people, often relatively newly qualified but full of macho bravado bull****, to try and go through the arch, or bottom out the Blue Hole, and that's what causes the deaths. You don't hear of many women, if any actually, dying in the Blue Hole...
Mark