I got some instant fastpasses once because of a mechanical delay at a ticket window. I asked the cm if they had to be used that day and he said yes. We lucked out because we arrived on Saturday afternoon and went to MK that evening just to see Spectromagic & the fireworks. We figured lines would be long so we wouldn't ride. I had to activate my AP and that's when we hit problems at the MK gate, the pass would not print. We only waited about 20 minutes. Without even asking, we ended up with 3 sets of instant fastpasses for any fastpass rides, so we got to ride that night.