Whatever, Jeremy. What you're telling me is that in both cases it would make sense to grab the shot you're after and then let the damned camera blast on for a few more seconds or minutes, recording nothing you'd want to keep. In the case of the first shot, I had no idea who'd come out of that door. I'd watched about six people come out -- most of them kids or tattooed teenagers. If I'd kept the camera in movie mode, grinding away, waiting for the next person to pop out I'd surely have filled a card before the shot materialized. In the second case, as I said, even if I'd been able to get the shot I got with the first frame of a burst, what would have been the point?
I've come to the conclusion that this whole thing is a futile discussion of something that simply doesn't make sense. I think Andrew made the point very well. When you get a really good street shot in movie mode, post it and we'll discuss it.
If I want to make movies I'll buy a movie camera. But I have absolutely no interest in making movies.
Crikey! Russ. You really do seem to be bound by a lot of rules.
Whether you decide to shoot in movie mode, or take a full-resolution continuous burst for 2 or 3 seconds, or just take a single shot, you should use your nous to determine which method would likely allow you to capture the best moment under the circumstances.
Obviously, if you see your card is almost full and you're not carrying a spare one, then it would be only sensible to stop shooting in movie mode, or alternatively delete sections of previous movie sequences, after assuring yourself there was nothing you wanted to keep.
Carrying sufficient memory for the style of shooting one intends to engage in, is a very basic, practical consideration. Memory cards are cheap nowadays.
In your example of waiting for someone interesting to emerge from a door, I wouldn't advise keeping the camera rolling unless there was a fairly continuous stream of people emerging from the door, that you found potentially interesting.
If you're looking directly at the doorway through the viewfinder, then as soon as someone begins to emerge, (you see the tip of his hat, for example), that is the time to press the movie button. During the next 2 or 3 seconds there might be a variety of postures and facial expressions, one or more of which are the best.
A similar procedure might apply to the situation of a man jumping over a puddle. Anticipating that something unusual is about to take place, you frame your composition in accordance with a pleasing sense of geometry (whatever), then as soons as the man begins to jump the puddle, you either hit the move button, or press the shutter button to take a burst of continuous frames for the following 2 or 3 seconds.
By the way, the reason I'm discussing this is not because I use movie mode myself, in order to extract the best still-image moment, but because of the potential I see in the new Samsung NX1.
Standard HD video is not high enough resolution for me, and I believe most DSLRs produce the 'rolling shutter' effect in video mode. The NX1 apparently has a global shutter in movie mode. In other words, each video frame is a full 28mp capture, downsampled and compressed, although I'm not entirely certain about this. The camera still seems to be in a process of firmware development.
Anyway, if 4k video stills do not provide sufficient resolution, and/or sufficient DR, the continuous frame rate is adjustable down to a slow 8fps, which should be fast enough to capture the perfect moment of someone emerging from a doorway.