Yeah, I was thinking the same thing for that one. I'm not sure why he picked it. I don't think Gibson as a director made any memorable movie (some are decent but I can't see them being in such a list).
I guess that's the problem with a list and no context. Without knowing what exactly he saw in it that he thinks an aspiring director should pay attention to then you can watch them, but to what end? The issue with being an aspiring anything is you likely lack the maturity and contextual awareness to glean knowledge from every experience.
Lee picked it because it's exceptionally good cinema.
Do we know this? Perhaps there's one scene that stands out; or he feels that the visuals are perfect but the story is terrible; or it's an example of how you can make great movies but still be hated; or ...