When Damon is eating a burger at Bree's bar and talking to Elena about Katherine, his beer bottle alternates from his hand to sitting on the table as the camera angle changes.
When Damon picks Elena up after she faints it shows her arms slung around him, when the camera angle changes her arms aren't wrapped around him any more, they are hanging down instead.
When Stefan is explaining to Bonnie that he needs to find Elena, he uses her vervain necklace so that Bonnie can do a connection spell. It is known that Vampires are burned by vervain, yet when Stefan is holding the necklace and puts it in Bonnie's hand he touches the vervain chamber directly. This would've burned him, but doesn't.