When dancing at the party when introduced to Sinclair and Maggie, the opening shot shows Mac and Sally, dancing, when camera starts to pan away from them, Mac (Rock Hudson) looks into camera when it pans away.
When Mac and Sally meet Jacques and Maggie at the airport, when they round a corner walking, a crew member's hand can be seen in the lower left frame as he adjust a cable.
After leaving the building where the waiter is killed in his apartment, you can see a boom mic along the bottom of the screen.
Mac cuts off a car to escape the assassin by turning left and immediately pulls over. The foot patrol cop runs over and asks for his license, adding "What's going on?" It's not plausible he would hear the tires squeal and be close enough to see the infraction but NOT hear the gunfire.