In her tantrum, Didi pulls a fish off a plaque that was mounted on the wall and throws it at Tom. When Tom was being questioned by the police later in the cabin, the fish was back on the wall.
In the climactic car chase, the two detectives and Cesare Danova are in a squad car with a siren flanked by two red lights on its roof. All the other squad cars, including Hope's, have a single red light on the roof. In the close-up of Diller squirting mustard at the detectives' car, they now have a single red light on the roof. This is followed by a shot of the detective's car leaving the road, which now has the siren and two red lights. Later in a closeup of the detective's car spinning around, it has the single red light again.
When Didi has her tantrum in the cabin, she throws the large green (unplugged) lamp at Tom, and we hear it shatter. When the police arrive for questioning, the lamp is intact, horizontal on the table, and illuminated.
In the opening scene, Lily (Phyllis Diller) prepares dinner and sets the dinner table with white melamine plates with gold wheat sheaf. Later on when the family sits down to dinner, the table is set with white china banded with dark green. Then after the meal, the dishes Lily washes have returned to the melamine.
While trapped in the fire shed, Didi had her foot firmly stuck in a red metal bucket. She pulled a cord that dropped the walls, allowing her to get out, but in the next instant, the bucket stuck on her foot has suddenly disappeared completely.
In all the scenes where any of the actors drive a car, you can clearly see that the column shift is in 'Park.'
As Didi (Elke Sommer) throws objects at Thomas Meade (Bob Hope) during their argument at the lake house, the size and coloration of the smudge on her cheek changes.
Tom goes to throw the double barrel shotgun on the couch and it goes off in mid-air without striking anything.
When Tom is carrying Didi inside the cabin after she escapes to fire tool shed, the numbers "3" and "4" can be seen on either side of the door. This would seem to indicate the cabin used on location for the exterior shots was a duplex, and that the filmmakers forgot to remove the numbers. Also note a pane of glass is missing from a window.
In the end-of-movie police car chase, Phyllis Diller's character rides a Honda motorcycle with a small displacement four-stroke motor. The engine sound, dubbed-in, is a two-stroke engine sound, which is incorrect for this type of motorcycle.
During climatic car chase Bob Hope is using the police radio mic. From behind chasing him the police fire a shot appearing to shoot the mic out of his hand. A visible fish line is attached to the mic yanking the mic out of Hope's hand.
In midst of big chase scene that supposedly occurs in Oregon, one scene takes place in front of Hollywood aquarium store.
When Bob pulls in to the lakefront house, a boom mic is briefly visible in the car windshield (twice).