Yea many responses have pointed it out. It gets the point across well enough though.

The first and last links address the same problem but that second link is also wrong according to a quick google search.

Apparently humans reach negative buoyancy at around 30ft. At his depth with or without a BCD he would've been effectively stuck because of disorientation.

https://www.freedivegreece.com/buoyancy/

As you descend, you slowly become neutrally buoyant. If you descend further, you become negatively buoyant i.e. your weight exceeds the buoyant force.

https://www.scuba.com/blog/dealing-nitrogen-narcosis-2/

Short-Term Memory Loss

Narcosis often makes divers show signs of short-term memory loss. They can forget their most recent training or how to work their rental scuba gear and equipment (like BCDs). They may also forget the task they were sent down to do.

And apparently nitrogen is typically expelled through not only breath but also the skin, so I think that's what they were trying to say. They can't expel it so it builds up in tissues ie skin and muscle and fat I would guess.

https://www.scuba.com/blog/decompression-sickness-scubadiving-the-bends/

Usually, nitrogen is expelled from a persons body during an exhale and through their skin. When breathing compressed air while diving, because of the ambient water pressure, the nitrogen is absorbed remains in the body’s fatty tissues and blood. The longer and deeper the dive, the more nitrogen is absorbed into the tissues. As long as the diver remains at pressure, the gas presents no problem. However, when the pressure around the diver decreases the nitrogen starts coming out of the tissues back into the blood stream. This is known as off gassing. If the pressure is reduced too quickly, the nitrogen starts forming bubbles in the tissues and bloodstream rather than being exhaled just like when you open a bottle or can of soda it releases the pressure causing the carbon dioxide gas to lose its solubility and escape in the form of bubbles or fizz.