Help with log please, unexpected behaviour

Dusk flight yesterday evening, all going well until I could see the quad swaying about so started to descend at which point, when I could see her clearer, she then starting pitching about too. Anyway, she landed fine, no damage.

In the video, you can see the front right arm dive across the front of the camera lens (0:19) which is clearly indicated in the log, then a minute or so later, the log shows her pitching quite badly for about 30 seconds, she’s fine after that.

I have been tuning the gimbal which carries a mirrorless camera so all up, the gimbal weighs >1.5kg so quite a heavy load although the quad is X8 with up to 20kg thrust. Initially I wondered if the gimbal had pitched violently but the camera holds level.

The graph attached appears to show Pixhawk countering the movement which might imply there was a temporary mechanical failure of some sort although the current graph doesn’t show any spikes apart from the event itself.

If anybody knowledgeable on logs could have a look, that would be great…