That's very strange and pretty sure there's no other reason why the night ends other than the four mentioned.
It being a glitch is highly unlikely as there has been no report of such occurrence up until now, and I'm sure someone amongst 40 thousand people playing the game would report such a thing.
Did the night end with the summary screen or did it crash in some way? Could you describe what you did exactly and the night ended? Could you check your stamina level in the "stats" before starting the night?
If you saw summary screen then it must have been either time or stamina (camera battery) that has run out