Fred's bowling ball gets smashed to pieces while he and Barney are in the bowling alley, but when the two of them are walking through the parking lot afterwards, Fred is carrying a bowling ball.
When Fred and Wilma arrive home from the movies it is dark outside but when they walk by a window in their house it is light outside.
When Fred and Barney go in Fred's house you see them go thru the front door but they don't appear thru the front window once in the house.