Is it possible to ride a bus as a passenger? Also, how do I get out?

I was trying to buy noodles from a vendor, to prepare to beat up a couple of unruly punks. As I was handing over my money (pressed the ‘buy’ button, which is right-click by default in the PC), a ‘Select destination’ screen (similar to a taxi ‘Select destination’ screen) appeared. I forgot if I selected a destination or chose ‘cancel’. Anyway, I next found myself inside a bus as a passenger.

I was then forced to ride inside the bus against my will (I was unable to exit by pressing right-click) as it went along its route. I’m not sure if the game detected the right-click as ‘enter the bus’ or if this is a bug. I was forced to reload a previous save, as this is no fun at all.

Screenshots (my character is the only passenger in the bus and wears a hat):
(click on an image to view the larger version)

My questions: Is this a bug or is there a normal (non-bug) way to ride the bus as a passenger (not as a driver)? Also, if I suddenly found myself inside a bus, how do I exit? (Right-clicking does not work in my case.)