As an avid VF spectator, because I can't manage to get enough continuous flying on video to enter (though not for want of trying
) I have, however become quite adept at editing my footage to use OOFs to cover up crashes and join to gether decent bits of flying to show my family & friends what I do.
I would say if you are concerned about editing, the time OOF is hardly relevant as I can (and have) made a kite fly out and back in from completely different segments of video pretty smoothly and look like a convincingly brief loop off shot. If you think about it, editing allows you to trim the time off screen; genuine OOF flying doesn't.
The giveaway is always the background and clouds. Stuff moves in the wind and if you look hard enough there's nearly always a discontinuity or blurring as the two shots are faded together.
I would say don't set the rules just to rule out editing - you should be able to spot it if you suspect it.
Long may VF continue (because statistically I will manage to keep a kite in the air for > 2mins eventually. Don't hold you breath though!)