Boy Ive thought about this for a while. I went to Ed Sheeran and decided to turn my app on just to see what the hits would be like and my phone went nuts so there are obviously rides to be had. To be honest what I would do is wait by Fireside Grill, call the passenger to see where they are at and if they are still in the arena cancel the trip. I certainly wouldnt of waited 20 minutes, you are allowed to cancel the trip and charge them for it which is what I would have done in your instance. But to be honest how much hassle do you want to go through for one ride.