Cellar Boy - S1-E21
Stupidity: Jamie is driving his Chevelle SS when he realises that he has no brakes. He's driving on a flat road. The car is an automatic transmission, and he doesn't shift the car out of Drive and into Neutral to stop the power and forward movement of the car. Instead, he shifts the car into Low before crashing the car into a Jersey barrier. (00:48:27 - 00:48:57)
Answer: It's a common cop show plot device. If the police on the show always acted in the most logical way (i.e. not alerting a suspect to their presence) the show wouldn't have the opportunity for an exciting foot chase.