I haven’t read the whole thread so this might have come up already but in case it didn’t here’s some gruesome details from the Byford Dolphin accident in the 80’s. It’s not perfectly analogous to what happened in the sub but it gives you an idea of what extreme pressure can do to the human body.
https://www.todayifoundout.com/inde...t-gruesome-death-the-byford-dolphin-accident/
Byford Dolphin was a semi-submersible offshore oil rig built by Aker Engineering of Oslo in 1974. Weighing 3000 tons and manned by a crew of 100, it was capable of drilling in waters up to 460 meters in depth. To allow construction and maintenance of the wellhead at these depths, the rig was equipped with a sophisticated Saturation Diving system built by French firm COMEX. On November 5, 1983, the rig was drilling in the Frigg Gas Field in the Norwegian sector of the North Sea. At 4AM, British divers Edwin Coward and Roy Lucas were resting in the dive chamber while Norwegian divers Bjorn Bergersen and Truls Hellevik were returning from their shift in the transfer capsule. The capsule was hoisted from the water and docked to the dive chamber by diving tenders William Crammond and Martin Saunders, allowing Bergerson and Hellevik to climb through a short trunk to join Coward and Lucas.The normal procedure was for the divers to first seal off the trunk and isolate the chamber so the tenders could depressurize the capsule and detach it from the airlock. But before Hellevik could close the chamber hatch, William Crammond released the clamp securing the capsule to the trunk.
The results were immediately and horrific. The capsule violently decompressed and blasted away from the trunk, killing Crammond and severely injuring Saunders, while inside the chamber the pressure dropped instantaneously from 9 atmospheres to one in an instant. Hellevik, crouching in the trunk, was blown apart, scattering body parts across the rig deck. One observer described finding his liver “complete as if dissected out of the body,” while part of his spine was found 10 meters above the chamber on the rig derrick. The other divers in the chamber fared little better. Autopsies of Coward, Lucas, and Berergsen revealed lumps of white fat clogging their arteries and veins – proteins which had cooked and precipitated as their blood flash-boiled. Mercifully, all four divers are believed to have died instantly and painlessly.