All units are directed to change to frequency 2. A close-up shows Reed's hand changing the frequency switch. The space immediately below the switch is clear except for a thin line of tape. When the full radio / speaker stack is shown a few seconds later, the space immediately below the switch has a piece of yellow card stock with notes taped to the radio face.
When Adam-12 is responding Code 3 to the command post it has flashing lights in the close-ups of the car.
In the overhead shots and long shots the lights are not flashing.
A portable transistor radio that size would not have been heard so clearly, so far away.
Malloy's policeman cap band glitters in the sun. Real policemen wear no glitter on their hats.
The "high powered rifle" (M16A1) 7.62mm round did not leave bullet holes through the wooden fence Reed was hiding behind when fired upon. Additionally, as the fence provided only concealment but not cover from fire, Reed should have assumed a crouching position to make himself a smaller target.
The Adam-12 station and location of the command post are 10 miles apart.