that seems as good as my theorys. You would get a decrease in airspeed one side and an increase the other.
The amount of nose drop is related though to the state of the trimmer. I had one which you had to keep your hand on the wheel while doing anything more than balanced turns. Half a boot full and it spun the whole lot out and you got some serious nose drop.
Any chance northsouth you can speed tape some string onto the fin top middel bottom. just U it around the fin and tape so it can't escape. And tell us what it does while yawing.