sfrecord~ vs video camera (audio not lining up)

Whenever I use sfrecord~ to record my patch's output, while simultaneously recording video (1080p at 24 frames a second, though i think its 23.93993whatever) the audio drifts over time.

Now I often record using a zoom H4n from the soundcard out, and that seems locked in step with the video.

Is there a reason why recording directly in the patch drifts? (or is everything else drifting?)