What can cause the camera to stop recording?

[handydude]

I was recording for about 30 minutes and it just stopped. I had it in airplane mode so that a call or text couldnt stop it and I still had space.

 

[Gregoris]

maybe that space was not enough to record any more

 

[SingingSabre]

maybe that space was not enough to record any more

This.

When you run out of recordable memory, the camera stops recording. Either free up space or switch to a lower resolution.

 

[adjuvantjfoster]

I was recording for about 30 minutes and it just stopped. I had it in airplane mode so that a call or text couldnt stop it and I still had space.

I routinely take video in groups of three files, each 25 to 30 minutes long at hockey games, one file for each period.
I have learned to start recording these games with an empty Camera Roll after I had the camera stop in the way you described.
My suspicion is that video files may be being recorded as one contiguous block, for performance reasons.
I have no way, today, of verifying my guess.