When he moves towards his right hand, his first step is with the left foot. For a moment, his heels are crossed. This is one of the things that allowed Pac to jump on him. For that moment, it's difficult to pivot, impossible to counter with power, the only answer is to pull back. But then with a guy like Pac you get attacked all over again.
I actually think Steward's footwork is better than Cotto's from what I see. But it appears Manny's at least working on where his body is when he's punching, which is needed.