One of the guards is shot, and the exit wound can be seen on his back. When he turns toward the camera, before falling, is it seen that there is no corresponding entrance wound.
Helm's car is smashed repeatedly by two other cars and emerges completely unscathed.
In the missile control room near the end, Tung-Tze's submachine gun has no magazine in it when he enters the room, but a magazine is present in a later shot.
In the closeups of the Allied Van Lines truck, the secret viewing ports and upper turret that open up do not match the number or location of those seen in a subsequent medium shot of the same van.
During the car chase, Gail Hendricks can be seen sitting much closer to Matt Helm in the shots inside the car compared to the shots from outside (behind) the car. Also the front seat is significantly different when seen from outside the car. It is a bench seat with headrests.
The rear shot gun bullet doesn't get through the phone book during the test but easily goes through the shooter's body a little later.
When Matt Helm slides off into the bathtub there are already several water stains visible on the sheets, including one where likely he was wearing a swimsuit, already wet from previous takes.
Lovey is seen to be wearing a bra after she supposedly climbed naked from the bath, been dried, and had a bathrobe placed on her.
(at around 1h 31 mins) Optical Special Effects error regarding the Allied Van Lines truck, supposedly with a helicopter inside. When the helicopter appears to be mechanically raised upwards from inside the truck, the incorrect background behind the helicopter of the blue sky and the fluffy white clouds also is raised upwards from inside the truck. When the helicopter flies away, the actual landscape of rocky and sandy hills, is seen behind the Allied Van Lines truck.
When Matt goes to his wet-bar to make a drink, the sound his hand makes in the ice bucket is of crushed ice, but each time he goes to the glass he drops in cubes.
The line to the squibs under Kovack's shirt, running down her leg, can be seen for a fraction of a second at the instant she is shot.
(at around 1h 40 mins) Sounds of a still camera autowinder in the ruined control room are heard as Tung-Tse is pointing a machine gun at Gail's head. It is heard several times throughout the scene, whenever the actors seem to strike a photogenic pose.
A camera is visible through the rear window of Matt Helm's station wagon during the car chase scene.