Throughout the series the rear-view mirror of Starsky's car is often missing when we see a two-shot of the guys in the car from the front through the windscreen. However in other shots of the car in the same scenes the mirror is almost always clearly in place.
In The pilot episode, both Starsky and Hutch jump/fall into a swimming pool. A close-up of Starsky in the water shows him in his blue shirt without his sweater, and his gun in his right hand. But the next cut to him shows him standing up out of the water with his sweater back on, and his gun in his left hand.
Frequently throughout the series, a criminal will be seen using a revolver with a silencer attached. A silencer is useless on a revolver (except for the Russian Nagant M1895) as the sound of the gunshot will escape through the cylinder gap, the space between the front of the cylinder and the muzzle.