Man that "started taking water at the neck seal" part is what gets me, that is the real pucker moment right there. I ran neoprene dry suits on pipeline work in the Sound for years and had a main zip freeze up on me at 60 feet once, not as deep as you but same deal, teeth gunked with sand and salt. What saved me was a chunk of beeswax and a soft toothbrush in my dry bag, scrub the teeth, wax them, work the slider slow, it will usually break loose. Now I wax my zip before every single dive and keep a spare slider and wax in the truck, that 20 dollar kit is way cheaper than a chamber ride. The neck seal leaking while the zip is stuck is the worst combo because you can't dump air right, so you did the right thing calling it and going up slow with your buddy.

I spent the first three years of my apprenticeship doing it backwards, chasing the number on the print and wondering why my finish kept drifting halfway through a run. My old lead, a guy named Denny who smoked like a chimney and never wrote anything down, used to tell me "the part don't lie, but the cutter sure will." Took me way too long to figure out he meant check the tool first before you go blaming the part or the machine. I finally started touching off every cutter before a job and my scrap pile dropped to almost nothing. Now I feel like a genius for doing the thing I should have been doing from day one.