When the Grinch finished loading his sled, he had turned all the Christmas lights off. As he was trying to take off, all the lights were on, but his sled stalled. His second attempt of taking off all the lights were off again.
When Martha May gives the engagement ring back to The Mayor, she holds the ring box out to him while he looks at the ring and her with his arms by his side. In the next shot, Martha May has her arms by her side while The Mayor is holding the ring box in both hands.