When the car runs off the road the window on the driver's side is clearly down. Later, below the water, the window is up.
When C.J. makes her comment about "the big guns," she is standing up straight. In the next shot, she is leaning on the counter.
When Hobie and Lauren kiss goodbye, they tilt their heads to the right. In the next shot, their heads are tilted to the left.
When Summer starts to tell Jackie about her new relationship with Matt, she puts her hands behind her back. It then cuts to a closer shot of Summer and her arms are at her sides.
Hobie introduces himself to Lauren twice. The first time is when she joins the guards, the second time is after she gives her reasons for wanting to be a lifeguard.