When Lois kisses Clark at the end of the episode, she has leg warmers on. Earlier when she is reading the Booster Gold folder, she doesn't have them on.
When Clark and Lois are walking down the street at the very beginning, they look across to a man in front of a magazine rack. In the close shot, there is a woman behind him looking at the magazines, in the long shot, he is alone and in the next close shot, she is behind him again.
Upon seeing Jaime Reyes, being a bumbling nerd, Clark claims that he was like that in Smallville. However, this is far from the truth, especially in regard to the fourth season, when Clark was the star of the football team at Smallville High School.
When Clark changes in the phone booth, his undershirt is blue. When Clark speeds into the building, his shirt is black. But as Clark watches Blue Beetle and Booster Gold's struggle, his shirt is blue again.
Even though it was hit by an energy blast capable of shattering metal, Clark's jacket had no burn mark or holes in it after the hit.
When he sees Booster's Legion ring, Clark deduces that he stole it. But Booster is from the 25th century, and the Legion wasn't formed until the 31st century.