Other mistake: Danny, while driving home with his family, hits a man with his car. Danny gets out of the car to attend to the man, but his wife, Linda, who is a nurse, does not get out of the car to render aid to the man. (00:02:18)
Through the Looking Glass - S5-E19
Other mistake: Danny supposedly handcuffs an at-risk teenager. When the police officer takes her away to a cell, the girl isn't handcuffed. The handcuffs are just in her hands behind her back. (00:52:00)
Milestones - S9-E12
Other mistake: First we see Jamie in a Ford CVPI with license plates 7554 like a couple of times before in the show, a minute after he's seen exiting a 2015 Ford Taurus with plates 82399. He answers a 10-85 while supposedly driving in the CVPI but somehow he manages to change in less than a minute to a Taurus. We see the exterior of the car, but the car's interior corresponding to the Taurus is seen a few seconds earlier. (00:03:35 - 00:04:20)
Other mistake: Danny says "14 years ago today I kissed Linda" but in previous episodes they were celebrating their 16th anniversary.
Other mistake: Eddie and her partner respond to a store selling sandwiches with contradicting prices. For example, grilled cheese is listed for $3.99 and $6.25, and tuna melt is $5.50 and $5.99, and BLT is listed twice on the same sign. (00:03:10)
Other mistake: Jamie and Eddie respond to a carjacking of a minivan. They are across the street and Eddie claims there's a baby seat in the car. There's no possible way that she could see if a baby seat was in the car. The minivan had dark tinted windows and only the driver's door was open. (00:05:00)
Other mistake: Throughout the episode, all the interactions with the characters went from day to night except for Commissioner Reagan chaperoning his grandson's class at the museum. It stayed daylight the whole time at the museum. (00:27:14)
Other mistake: Jamie races to the patrol car after witnessing a car jacking with possible child inside. He flings the door open, gets halfway inside, and the car starts without him even being close to turning the key in the ignition. (00:04:00)
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.