When Craig spills the beer on himself, it leaves a foamy stain on his collar. The stain vanishes in the next shot, then reappears in the next.
When Craig discovers the little boy in the water, it is obviously a dummy. Then, when he brings him in, the boy is supposed to be unconscious but can be seen blinking and smiling.
When Mitch reads the details off the fake I.D., he quotes the weight as 350 pounds. However, the close-up of the I.D. says 175.