Wow BondoFox! The wrists are the first body part to loose circulation when restrained. Many times the person getting tied up is distracted enough by their adrenaline rush and heightened dopamine levels from all the fun they're having. Things like that creeps up on them without much warning beside the skin changing colors. Good to hear they're alright.
As for myself I've had my share of tie up fails over for all the years I've been into bondage; mostly involving self bondage. The time when I tied myself up with tons of rope a little too securely to a chair resulting multiple knots tightened while I was play struggling.... was all alone in my apartment and it took about 4 hours to get out of that one but I was fine.
Sometimes when tying myself up and a knot or two would come loose, rope would slip down and I'd spend more time trying to tighten it than enjoying myself being tied up. Still have to improve my rope skills. Or the rope would be so tangled up from being tossed in the closet from the last use I would give up in frustration trying to untangle it. Thankfully these issues don't happen with duct tape.
There was a time when I was a teenager exploring my interest in bondage and I duct taped myself to a chair in my bedroom when my parent's left to run errands. They returned earlier than expected. My father called down for me to help them and heard the sound of duct tape from my room. Naturally wondering what I was doing he went up to investigate and knocked on the door. "What are you doing in there?.... *tries to turn door knob* Why is the door locked?" Come down and help us unload the groceries from the car!" If the door hadn't been locked he would've walked in despite it being closed and I would have some explaining to do.

He never asked but he knew something was up.
Most recently I was tied and tickled by a guy with not much bondage experience a few months ago. He put me in unpadded ankle and wrist cuffs (not a fan of these since a lot are cheaply made and don't fit right) secured them to his bed without giving the rope much slack. It was a lot of fun...until I twisted my left wrist from enthusiastic struggling and gave myself a mild sprain. Since I was gagged I couldn't tell him something anything wrong... thankfully he stopped about a min later since he noted my moaning in pain and I told him I probably injured my wrist when he took the tape off asking what was wrong. Took about a month for the sprained wrist to heal due to twisted ligaments. I'm fine now thankfully but that was my first somewhat scary bondage injury.
Going to emphasize to guy's to be careful tying wrists, use well padded cuffs if and give the rope enough slack to move my arms a bit.
Don't let these things put you off to exploring your interests in getting tied up and/or tying others but you should know how to play safe.