Im going to take a stab at this.
I would imagin that with a swept wing aircraft (as the T-tails are) with the movement of the center of pressure forward (due to tips stalling first) that the overall pitching moment is nose up as the center of pressure moves infornt of the c of g.
As the tail is in a turbulent airmass then its effects will be minimal.
Waiting for the corrections.......
Nick