We post customer service horror stories every once in a while, but there are always more. Everyone has a story from their past that they'll never forget.
At Cracked, those became image macros that will make you feel better about your experiences. Or maybe you have one even worse! If you do, tell us about it after you see the 19 that made the cut.
#16 is the customer's fault primarily. Air Canada has a well stated cutoff for check in, and while they can sometimes flex it slightly if you don't have bags to check, if you do, they have no way to check you in, you've missed your flight. I know, because both I and friends have been 5 minutes late. :) it sucks, but you deal. They'll usually rebook you no problem though, so I suspect the rest of the story is a result of dealing with an angry and persistent passenger.