I was walking past when cp was having his bladder problem... it's quite disconcerting to see a grown man in a public park with bladder problems

, but anyway... this was definitly an unusual event; one end of the leading edge still pumped tight, while the valve was open, and the rest was flat?!?
I don't think it so much of a twist, but more of a folding of the bladder. That is, the bladder folded on itself and pushed itself tight against the wall of the leading edge. The bladder didn't feel twisted. "How the hell it pumped up in the first place" is a good question though.
Old kite manuals recommend pumping a kite halfway, or just a bit more, and then massaging the bladder to ensure kinks/twist don't occur... and using talcum powder to lubricate the bladder/LE.
cp, just out of curiosity, was there any powder/talcum inside the LE when you took the bladder out?