Thank you for sharing this.I've had one myself, so I thought I'd give you some insight. Mine occurred at 25m. I was carrying a pony, and my initial action (there was no thought it was an automated response) was to switch to my pony since it felt like an OOG - this didn't solve the problem and looking at both my spg showed 50% and 100% respectively. All the time I'm trying to breath and getting nothing.
I suppose all this took place over 10 perhaps 15secs. Instinctively I headed for the surface - I didn't think to inflate, I just kicked. We were in the Red sea so 50m+ Vis. I distinctly remember the speed my brain was working at, it was like reading 4 column of text on a page simultaneously. The surface seemed so far away and seemed to take forever. My log showed I covered 12m in around 30secs. At 10m the laryngospasm cleared and my exhale was so violent it caused a mask flood
My wife (my buddy) just saw me take off in her peripheral vision, initially thought maybe I'd seen something and followed me. when she reached me I was finishing a mask clear. she asked if I was okay, my response was yes and we continued the dive - albeit at 12-15m I was conscious to not surface quickly incase I had come up too fast. I gingerly swapped regs back and forth but had no issue. The reg in question once we got back was thoroughly inspected by a very trusted individual who was looking for a cause, but no fault found. We presumed that somehow I inhaled a bit of water which trigger the event. At this time I was approaching 500 incident free dives, and I've logged 700 dives since with no repeat
Had someone tried to intervene and restrain me or try to force another reg in I would have hit then, since my body was in survival mode and acting instinctively