Failure to Appear is failure to comply with a court summons, not failure to pay a parking ticket. There is definitely more to this story.
Get a ticket, you get a choice between paying the fine and appearing in court to contest it. Guess what happens when you do neither.
It was a pretty eye opening experience. Especially on the arresting officer's part because they get no clue as to why they are arresting you beyond "FAILURE TO APPEAR" that shows on their screen, so they assume the worst.