I'm a Dirrell supporter but I think he was on his way down even though their feet got tangled! I also think that Abraham got spared a KD by the ref
Had this been in the center of the ring and the same punch/push landed Abraham would have hit the canvas and it would have been called a KD. The only factor that changed it was him being held up by the ropes. It should have been called a KD. Just as Abrahams KD in the 10th should have been as well. Neither were deciding factors in a lopsided fight up until the DQ.
If it had been called a knockdown, then it would have been incorrect as no legal punch landed. You're not trying to claim that Dirrell did land a punch, right? So you're basically arguing that the referee probably would have called it wrong if it had been in the middle of the ring, so should have called it wrong here too? I'm not sure what your basis for knowing that can possibly be...