When Cal begins telling Emily how to re-light the water heater pilot he tells her to open the gray door by sliding it down. As he finishes the directions he tells her not to forget to slide the gray door, "back down", presumably to close it.
When Bernie finds out that his daughter is in love with Cal he drives over to the house where Emily and the Weaver family are living. When he runs around the corner of the house, Robbie immediately calls out "Jessica!" even though she is not yet visible and Robbie can therefore not know Jessica is also coming.
When Jacob summoned Cal for the first time in the bar, Cal's drink does not have ice anymore but when he approached Jacob's table ice magically appeared in the drink. Also, the orange slice on Jacob's drink shifted to another position when he asked Cal to take a seat.
The goof items below may give away important plot points.
Cal tells Jacob that he has only slept with one woman. after he sleeps with Kate, you see him pick up an additional eight women. later, when his wife finds out he slept with Kate, he says he has now slept with nine women. If you add his wife, Kate, and the other eight women, that would actually equal ten women he has slept with.