Visible crew/equipment: After Louis makes the promise to Ellie by telling her, "Church will be fine," Louis heads out the door and down the stairs. The reflection of the boom pole/mic is visible on the red vehicle's windows, just as Missy drives past Louis. (00:16:00)
Visible crew/equipment: As Rachel runs to the airplane through the line of passengers, on her way back to the house from her parents in Chicago, you can see lighting equipment reflected in the glass window, before it cuts away. (01:11:00)
Continuity mistake: When Ellie falls from the tree after the rope from the tyre breaks, Louis runs with his wife to see how she is. Louis is wearing a plain white crewneck T-shirt with the sleeves rolled up. When Rachael yells "Gage!", you now see Louis wearing a striped white unbuttoned collared shirt and sunglasses. When Louis is running for Gage, he's back to his plain white T-shirt with the sleeves rolled up. (00:05:40)
Answer: Because in the book, the sign at the entrance to the "Pet Semetary" was written by some anonymous child. Clearly he/she couldn't spell that well yet.
Grumpy Scot