Re: the pull back
Name me any great fighter that used the pull back counter.
Ali is the only one that comes to mind. But he didn't use it anymore after slowing down a bit. And if it wasn't for his amazing chin, he probably would've been KTFO several times during his career.
There are many very good fighters who occasionally use it, but the ones that use it as a primary defensive counter move eventually get flattened. Zab Judah, Michael Nunn, Hearns, Benitez, Herol Graham, Naseem Hamed, etc...
Actually, Antonio Cervantes used it successfully, but against mainly limited comp. I'm sure Duran would have timed it and made him lean all the way back to the canvas.
Now, if you're talking about the fade away a la Floyd Mayweather, that's different. That involves a half step back and slight head movement to the side. It's not leaning back.