Hutch has his police light attached on the roof driver side on his way to Monique's house, but when he arrives, it has moved to the passenger side.
Starsky misses his pool shot. When Hutch takes his turn the position of the balls have changed.
In the Precinct scene you can see the microphone power pack bulging under the back of the actors shirts.
Hutch states that they should be able to left some fingerprints, yet moments later he picks up the phone receiver with his bare hand. A cop hoping to find prints would never do that.