Continuity: During the diner scene with Keith, Veronica and Lamb, Lamb leaves and Veronica starts to go next. As Veronica starts to leave, still sitting in the booth, she puts on her hat (right after she says to Lamb "smell ya later"). The camera angle is on Keith, but you can barely see Veronica putting on her hat. In the next shot, the angle is on Veronica who is just packing up her books. She has no hat on, but then puts it on (again).

Continuity: When the video of Kimmy plays on the school announcements, and she talks about Duncan being hung up on Veronica, there is a cut to Duncan reacting with raised eyebrows in the foreground, while Veronica can be seen in the background with a passive expression. Then it cuts to a close-up of Veronica having a visible reaction with her whole face falling. But since Veronica and Duncan were reacting to the same thing, Veronica's reaction should have been visible in the first shot as well.

Plot hole: When Veronica tells Mac that she was switched at birth with a girl who was born the day after her in the same hospital, Mac repeats that the girl's birthday is the day after hers, as if she already knows what she's about to read on the paper that Veronica gives her, which is that she was switched at birth with Madison. That would make sense, because Madison was making a big deal about her birthday earlier, and it's reasonable that everybody would know when it is. However, if Mac and Madison were sent home with each other's parents, then they were also assigned each other's birthdays, meaning that even though Madison was really born the day after Mac, Madison would celebrate her birthday the day before Mac celebrates hers.