While I’ve not been stabbed or stung by a sting ray, I have been splashed by molten steel and do regularly dig hunks of metal out of my body and I can tell you that when you experience the level of pain that Irwin probably did, your first reaction is not grab at the object, it’s to scream and thrash about, both actions would be fatal for a diver. When I got burned by the steel, I was holding one end of the shank which held a ladle filled with about 100 lbs of molten steel. It took everything I had not to drop the damn thing and run around screaming. Of course, had I done that, I would have sent molten steel spraying all over the place, which would have burned myself and everyone else in the vicinity. I stood there, screaming for help, holding onto the thing, until one guy was able to relieve me, then I ran off the pouring floor stripped off my gear, and dug the steel out of my back. At that point, all I wanted to do was just curl up and pass out some place, however, one of the guys came over to me and said, “You coming back?” and because I didn’t want to appear the wimp, I nodded “yes,” put my gear back on and went back to pouring steel.
If the pain Irwin went through in his final moments was anything like mine, he had to figure out what happened to him, control his body’s instinctive pain reactions (screaming and thrashing about), grab the stinger, and yank it out (ignoring the additional pain that this would be causing him), then head for the surface. It is not an easy task.