Plot hole: Matlock figures out that The Professor wouldn't have been able to see the security guard from 50 yards without glasses, and that's what tips him off about The Conspiracy: the guard testifying that the man wasn't wearing any. However, when we see the scene happen at the beginning of the episode, the person posing as Prof. Erskine Tate is, in fact, wearing glasses. (00:04:15 - 00:22:15)