In his review of The Dark Knight, he regrets his initial lukewarm reaction to the film, based largely on his distaste for Batman simply walking around and hitting people rather than his clever tactics from Begins. Then he figured "All these great themes and ideas, and I'm complaining about how he beats people up?"
He grew to feel this about his Minority Report review, as he came to see it more as an attack on Steven Spielberg and Roger Ebert than an actual review of the movie. He actually said it was his biggest mistake so far, took it down and uploaded a version of the review that removed all the personal attack on Roger Ebert and (paritcularly) Spielberg.
While reviewing The Last Airbender, he apologized for his overly broad statements about anime in his Spirited Away review, ironically while falling into the trap of thinking the Avatar franchise is anime.
He put out an addendum to his review of The Incredibles, after it became clear that his repeated attacks on the film going too far into Darker and Edgier territory made it sound like he thought the film should be Tastes Like Diabetes instead, when actually he just wanted more of a balance, like in Pixar's other films.
His review of The Prestige is apparently this, given that he completely misunderstood the twist ending (thus living up to the more obvious interpretation of his name) and that the video seems to have vanished from the face of the Internet.
Promoted Fanboy: Joked about by SF Debris in his review of the Star Trek: The Next Generation episode "True Q." The credits of that episode mentions "Matthew Corey" as having come up with the basic plot. Chuck jokes, "If you want some further info on the subject, perhaps he'll chime in. I have the feeling his words will get you farther than the film will ever go." This is a reference to Confused Matthew's theme song. Matthew Corey's YouTube comment reads "Hey man, Thanks for the shout-out! For the rest of you, I am not 'Confused Matthew'."
Roger Ebert: Despite his personal claim in his original Minority Report review intro that "Ebert isn't a critic I often agree with", as of his Moonrise Kingdom review, he has agreed with Roger Ebert exactly 100 times, leaving a total of 71 disagreements.