If all else fails you can twist the yoke on your first stage to break the O-ring seal between the valve and first stage. The oring will fly off but shouldn't go to far.
The boat captain did this to me in the Philippines once. I had 800psi at the time.
I was sitting on the deck unclipping myself from my BC when I heard a big blast right behind my head. The boat captain wasn't a diver and didn't know I had to purge my reg first. Sometimes you can be a little too helpful.
The O-ring landed right by my tush.
Edit:
nvm, guess you got it settled.
The boat captain did this to me in the Philippines once. I had 800psi at the time.
I was sitting on the deck unclipping myself from my BC when I heard a big blast right behind my head. The boat captain wasn't a diver and didn't know I had to purge my reg first. Sometimes you can be a little too helpful.
The O-ring landed right by my tush.
Edit:
nvm, guess you got it settled.