Continuity mistake: At the beginning of the first episode of Season 3, "The Aftermath", Ryan's hair is much shorter than it was at the last episode of season 2. Since they arrive at the hospital with a bleeding Trey, we know that this is right after Trey got shot. It doesnt make any sense that Ryan would go get a haircut right after Trey got shot and then go to the hospital with him.
The Shape of Things to Come - S3-E2
Continuity mistake: At the beginning of the second episode of season 3, "The Shape of Things to Come," Summer, Marissa, Ryan and Seth are ordering pancakes at the restaurant. In this whole scene, Marissa's blue mug keeps changing position between shots.
Answer: She is referring the episode entitled: The Best Chrismukkah Ever, episode 13, season 1. She goes out christmas shopping with Ryan and gets stopped by a security when she is out by Ryan's car. He asks to look inside her bag and finds a stolen watch and some other stolen things.