It's is a matter of record that he never learned how to do it.Watch him against Machen, or anyone else who does not come to him. Watch this clip at 49.48. Liston never mastered lateral movement, he followed you around. https://www.youtube.com/watch?v=WAl9XDCCCHQ
I tend to just favour Liston here simply because he had the better chin in a fight where I think a lot of bombs would be exchanged. This Mendoza fella though portrays Louis as some multi flawed inferior being which is quite astonishing for someone who defended the title 25 times against all comers. I mean how the hell did a fighter with such a weak chin, poor defense and plodding feet achieve such a thing.
Louis was a world rated fighter from 1934 until 1951. Considering all those defects he did rather well.