I don't use the video camera enough to notice that it does it, but it sure does.
I dug through the settings (as I'm sure you have) and didn't find anything obvious.
A quick search through Google finds the answer below, which sounds right-ish to me. I've noticed before that you can take still pictures while recording, this must be the reverse of that.
"that's because you are NOT changing between photos and videos.... the middle button is to capture pictures, and the top one is to capture videos... they made it this way, so you can do both at the same time...
mostly noticeable when recording a video, start recording, and you can take pictures while recording, just using the middle button...
that's why you can access both picture and video settings....
hope this helps!"