Here is my real life story - had an SR-1 (Yoke) diving primarily cold waters of Great Lakes. Didn't have much issues and as I moved into tech, I changed to APEX DIN regs. The SR-1 became my travel reg but was also used by my son locally when we dove together.
We go on one of the charters and the first dive is to ~125 ft wreck; as we get to ~90 ft I hear a loud noise and the SR-1 used by my kid (he was 16 yo at the time) is free flowing violently. Not a build up free flow but gas is bursting out. No problem, gave him my primary (although he had a pony), closed his tank valve, wait a minute, reopen, looks fine. Keep the dive going but remain close to the line just in case. Finished the dive uneventfully and then we go to the next site. This time a wreck with a bottom at ~90ft.
We entered the engine room and my kid "thumbs" the dive. No issue, we get out and head back to the line. Then I see him deploying his pony. Looking at his gauge (attached to the hip D ring) I see he still has 1100 PSI so I think he wanted to practice pony deployment after he had that free flow before. Make our ascent with the safety stop and he goes first up climbing the ladder. I do my exit and take my time with my doubles and I see the kid and couple of guys messing with his tank. Apparently they could not take the reg off the tank because it would not depressurize. Bottom line, all LP ports stoped working (primary, backup regs, inflator for the wing, inflator for his dry suit) but HP ports still work hence I saw the pressure reading. After several hours water comes out (I guess got thawed away) of the 2nd stage.
Sent it to Sherwood quite upset (the reg shall fail by providing gas, not locking all ports) and eventually got an SR-2 as a replacement. The story I got back is that technician messed the service kit and installed O-rings in the wrong order. I was told that they updated the service kits by color coding o-rings after that. Still have the SR-2, use it for rec trips to warm water destinations, never had another problem and a fantastic breather. Said that, I don't think I would trust it again in cold water.