T Tail question

After an exhausting session with Victoria's Secret Police, "Paul
Austin" blurted out:

Something I saw raised a question in my mind: An MD-80's T-tail had
one half pitched up and the other half pitched about neutral. My
question is why any T-tail aircraft would allopw differential motion
of the two halfs of the horizontal stab? It seems to me that the
rolling couple such a position would impose in flight would act as a
tremendous shearing force on the fin.

I've jettisoned all my DC-9 and MD-80 manuals, but look at this
link... http://142.26.194.131/aerodynamics1/controls/Page2.html

Scroll down to the part about Tab Controls, that's how DC-9s' and
MD-80s' elevators work. That "split" elevator thing you saw goes away.
It always makes me pause and think, "WTF were those engineers
thinking?"

Now the Boeing 757...there's a tits machine!

Juvat