When Sheldon mentions his enemies list, he names a bully from his childhood who put dog poop on the handlebars of his bicycle. Since it's been established in other episodes that, growing up, Sheldon eschewed anything other children would consider fun in order to pursue his scientific interests, it's out of character for him to have owned a bicycle, although he might've gotten one as a hand-me-down from his brother, since he is seen riding one when he got a paper route in a chapter of Young Sheldon.
While talking with Raj and Sheldon; Stuart has his back to the camera. From that view it can be seen that on top of the stack of comics that Stuart has in his arms is a Superman comic. But during the conversation the comic changes to Flash comic.
When Leonard takes the napkin from Sheldon, his fork disappears from his hands, then reappears.
When Sheldon starts listing the cards Wil Wheaton can play, his left fingers are near the top of his cards. It then cuts to a shot of Sheldon from behind, and these fingers are lower.
The Dixie Trek sci-fi conventions, including the 1995 one, were always held in Atlanta, Georgia, never in Jackson, Mississippi. The Mississippi convention was Coast Con held in Biloxi.
Since Stuart owns the comic book store, he would have been ineligible to participate (much less win) the Ka'a tournament.
Sheldon describes Wesley Crusher from "Star Trek: The Next Generation" as having an eidetic memory. However, it is never established in that series that Wesley has an eidetic memory, only that he learns quite quickly.