A guy picked up a wheel he'd left to have a tire replaced on while Jim Ayyy and I were away. The attending technician had made a note that this rear wheel had a broken spoke. The rim had a noticeable wobble.
Based on tire and rim size we guessed the bike would have cantilever brakes. Jim Ayyy pointed out the spoke problem to the customer.
"You got a broken spoke here. The wheel is going to have a big wobble in it. Your brakes might not work and the pads could cut the new tire," said Jim.
"Hey, I'm not in that race over in France!" the guy said, laughing patronizingly at our obvious attempt to sell him unnecessary work. "I'm just riding that bike path!"
Jim made a couple more well-meaning attempts to explain. The man kept insisting that he wasn't riding that race in France, so a straight wheel and functioning brakes were completely optional.
Wait until he comes back saying, "You just put this tire on my bike and it blew out."