Mr. Brooks tells Dawson that he returned to Capeside after making his first picture in Hollywood and never looked back. But he actually directed 9 pictures in Hollywood before returning to Capeside.
When Dawson returns to Mr. Brooks' house to retrieve his camera, he picks it up and put the lens cap on. Then, when he puts the camera back on the tripod to continue filming, the lens cap is still on (which wouldn't allow him to film). It cuts to Mr. Brooks, then back to Dawson, and the lens cap has disappeared, without it being removed by any of the characters.