Well, you can't really expect a guy to learn all those pesky signs in just five years, after all. To be honest, I never got the impression that Addison Russell was smart. Even before the abuse allegations came out, something just seemed off about his interviews. He used a lot of cliches (some of used incorrectly like the bartender in Boondock Saints), often times if a question involved any sort of critical thinking his answer would basically have nothing to do with the question. At the time I gave him the benefit of doubt and assumed he was just not a great public speaker, but based on what we know about him now I think he's just a moron. It doesn't surprise me at all that he would not know or at least be able to identify signs.