Continuity mistake: When Ryan is lighting Marissa's cigarette with his, at the start of the shot it's full, then the shot goes to Ryan and it's still full. But then the shot goes to Marissa and if you look at Ryan's cigarette you can see it is almost all gone. Then the shot goes to Ryan and the cigarette is full again. (00:09:00)
Deliberate mistake: Lindsay is not at Caleb's funeral in the last episode of season 2, "The Dearly Beloved". It's unlikely that she would have missed it - she is still on good terms with him and he is her father, the only reason she left was to be with her mother, not because she didn't love Caleb.Obviously they didn't want to create another drama with having Lindsay there while they had to focus on the important story-lines - Caleb's death, Kirsten's drinking and Marissa shooting Trey.
Continuity mistake: When Marissa is dumped on the driveway by Summer and Holly, Ryan first sees her there her left arm is across her chest with her elbow sticking up. The next shot of Marissa her ams are straight and spread out, and the next they are close by her sides, which is impossible for her to have moved them herself as she is unconscious. (00:34:15)
Continuity mistake: Season 4 - Episode 8 - The Earth Girls Are Easy - When Kaitlin is at the party, talking to Bullit, her strand of hair changes from hanging over her eye to hanging down next to it, without her moving her hands or head to displace it.
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.
Continuity mistake: When Kirsten and Ryan are talking while setting up for the Casino Night, the camera cuts between Ryan And Kirsten while they talk. Whenever you see both characters in one shot, her fringe is forward, but when you see the individual shot of her, her fringe is pulled back behind her ear. (00:18:10)
Continuity mistake: In this episode Seth, Ryan and Kirsten arrive at the country club in the Range Rover to get the boys ready for Cotillion. In the next scene we see Sandy with the surfboards in the back of the Range Rover as he has just come home and Jimmy arrives to apologise, soon after we go back to the country club where Seth and Ryan are trying on jackets and meet up with Marissa, Summer and Luke, proving that the Range Rover should still be there, not back home.
Continuity mistake: At the part where Kirsten brings Ryan and Seth to help set up the hall, Seth starts to blow up balloons with helium. In one shot he has an orange balloon under his arm and is tying the bottom, and the next he's starting to fill up a different balloon, without time to finish tying it and pick up a new one. (00:15:50)
Revealing mistake: The phone message that Ryan leaves on Luke's voicemail is different to what he originally said, which is "I want to make sure you took care of it. Take care of it," but the message recorded is, "I'm just calling to make sure you took care of it. Take care of it." Also the background sounds from the club - the music, people talking, etc, are missing.