Marissa leaves the bar without her purse. When the gang finds Marissa passed out in the alley, at first Ryan is not holding the purse. However, when Ryan runs over to check on her he has the purse in his hand and sets it down. He then grabs the purse as he picks up Marissa from the ground. Yet in the next shot while Ryan is seen carrying Marissa, you can clearly spot the purse laying on the ground.
When Seth and Summer are in the diner, Seth pushes the plate of toast closer to Summer so that she could have some. In the next shot the plate is back to where it originally was, closer to Seth.
When Ryan and Marissa wake up in the motel together, Ryan is holding Marissa's left hand as they are cuddling and her right hand is rested on her pillow. As he pulls away from her in the next shot her left hand is tucked under her right hand and her right hand is leaning against her head.
Several times during and after the scene where Marissa catches Luke, you can see the shadow of the camera on several of the characters.