So, what I noticed: the time of recording when it happens if various. I tried to reproduce it, and after 10 mins nothing. There was a little stuttering on the preview even before. What's interesting: the video contained a lot of movement. (playing dogs). The ultrastutter and hang appeared when I quickly turned the device, so the area recorded was dramatically changed.

A couple of other observations: the timers (time avail., time elapsed) were stuttering too.

Maybe it's the compression-intensity related?