All three of My Pan Cams do the same thing from time to time then later just stop doing it.
My sample of 3 affected, the actions I mentioned stopped two of them, the third still was acting up till I reset the settings on that one. only other unit left in the house has not been upgraded yet. Will try your experiment on it when I get a chance.
Both my cams were doing this until I removed their SD cards. Now they thay fixed in the correct direction with no uncommanded rotating.
Mine also do that all the time with Me doing nothing