Was flying today at night. Was a bit cold, a little windy, but overall was fine. Have 10 minute footage where everything goes smoothly, besides one tiny moment, which i think i have to pay attention to.

Doing this turn, the camera is a bit shaky here. You can see in this video.

What do you think is the reason for this? Rest of the flight everything was fine. So i dont think this is about wind.

any ideas anyone?

Don't know but the turn or rotation is much to fast to make watchable video.  If you did it slow it probably wouldn't shake either.

As hummingbird says, the pan is way too fast. Go into the settings and slow down the yaw speed. Any movements of the camera should be slow and smooth.