Visible crew/equipment: At the end of the third act, when Diesel and Walker line up at the lights to drag the quarter mile beside the train tracks, you'll notice the reflection of two crew members appear in the back of the side view mirror of the Charger as they approach it to get the steadicam close-up of Diesel telling Walker that on green, he's going for it. (01:31:35)
Continuity mistake: In the beginning of the movie when Brian drives the Eclipse, if you watch closely he redlines then shifts to second. The problem is that when they show the over head picture he shifts into second once again. (00:03:29)
Revealing mistake: In the truck chase towards the end, Leon says "I got her, you get Vince off that truck." While he speaks he is speeding along, but his tachometer and speedometer read zero. (01:21:10)
Continuity mistake: In the scene in which Jesse is shot watch his legs. In the first shot his left leg is crossed and under his right leg. In the second shot both his legs are stretched before him. (01:31:27)
Continuity mistake: When Brian is topping out his car in the stadium parking lot at the beginning, it looks like he's shifting and steering with the same hand, as the shot is reversed. Easiest way to tell is the "Sparco" on his seat is backwards. (00:03:29)
Continuity mistake: In the scene where Dom, Leon and Letty arrive at that place where Brian and Mia are calling the ambulance to rescue Vince, you can see that the car whirls up some dust so the front of the car is covered in dust. In the next shot, however, the car is clean again. (01:27:15)
Continuity mistake: On the very first race (in where Ja Rule takes part in the event), Dom (Vin Diesel) is driving a red Mazda RX-7. After the drivers line up on the starting line, Dom lifts up the passenger seat cushion to his Mazda to reveal a nitrous oxide system with a spinning nozzle and two gauges. Immediately after you see Dom spin the nozzle open, the camera does a close up of the nozzle and gauges in the next shot. Note how the gauge frames extended out from the surface (a good distance) then turn completely flat for the close up, even the nozzle gets shifted from one side of the guages to the other. (00:16:00)
Revealing mistake: When Leon is told to go and get Letty after she is pushed off the road by the lorry, you can see skidmarks on the road from previous takes. (01:21:10)
Factual error: In the final drag race against the charger vs supra, when Dom launches the charger it isn't smoke coming from the tires as it dissipates very quickly, indicating it's a fog machine or something similar. And as every car guy will know, two things that happened during Dom's launch are both possible separately but legitimately impossible to do at the same time, as we see Dom pulls a wheelstand while his tires are spinning. It makes for a cool shot but physically impossible, you need traction to do a wheelstand meaning zero or minimal wheel spin, and if his tires were doing a full blown burnout, he could not have gotten the front end to come up as it does. Not to mention as he pulls a wheelstand, the entire front end comes up before the car even started rolling, if it was a true wheelstand, it would've gone at least 7-8 feet before the front end reached max height.
Continuity mistake: In the scene of the "race wars" when Jesse runs against the Johnny Tran's Honda S2000, at the moment when Jesse pushes his NOS button, his car has a red racing steering wheel, maybe a MOMO wheel, and three gauges on the "A column" (at the left of the windshield column) of his Jetta. When the shot changes to Jesse when he says "ha," the red MOMO wheel becomes in a grape Jetta wheel without NOS buttons and the gauges disappear from the car. (01:13:05)
Other mistake: In the scene where Vin Diesel's Dodge Charger crashes, the blower is bolted on the bonnet. That is impossible because the blower is actually bolted onto the engine and it should shake with the engine's movement. (01:37:40)
Continuity mistake: This mistake occurs during the first racing scene between the four guys. It happens after Jesse and Ja Rule look under the hood of Brian's Eclipse. As soon as Brian says 'Am I worthy?' and he is in the middle of his sentence, it cuts to a different camera angle and shows Brian smiling but not moving his mouth while his words are still being said. (00:14:40)
Continuity mistake: In the scene with the first race between Diesel & Walker, the 2 girls spray paint a wide and very faint red line across the street. When the cars pull up to it, the line is now very distinct and only a few inches wide.
Other mistake: When Brian is practising in the stadium lot, when he shifts up there is a shot of his speedo indicating the car jumps from approx 127mph to 140mph in the space of a second. Questionable as that acceleration rate is, rolling on from that speed, in the 2nd subsequent scene right after Brian tells Harry that he needs NOS, he says "my car topped out at 140 miles per hour this morning". Although it is true that we don't actually see the needle go past 140mph, there is no way a vehicle would or could accelerate at that rate and then suddenly plateau at its terminal velocity. All vehicles' acceleration rates decrease rapidly as they approach top speed. At the rate Brian's needle was moving from 127 to 140mph, one could speculate that his actual top speed would be more like 200mph. (00:03:25 - 00:09:30)
Continuity mistake: When Brian pulls up in his red pick-up truck, note the distance from his truck to the car in front, this distance is is reduced somewhat when you look in the background in all following shots. (00:04:00)
Continuity mistake: During the scene at the Diner when Brian is asking Dom for a slice of the action on how he makes the extra cash for car parts etc. Right as Brian says "Now whatever it is you're in on, I want in on it to", we see Dom with a grin on his face, the camera then cuts to a closer view and the expression on his face has changed. (01:05:50)
Character mistake: When Brian looses the race against Dom, Dom states that Brian didn't know how to drive and was 'granny shifting' instead of 'double clutching like you're supposed to'. Double clutching is NEVER done in drag racing as it requires twice as much time to shift and is ONLY done when down-shifting. It is used to synch the engine RPM with the speed of the wheels but new cars have syncros that do it for the driver. (00:22:00)
Other mistake: When the cops get prepared before arresting Johnny Tran, a cop inserts a magazine into his M4. If you watch the rifle's chamber, you can see the green plastic thing that is at the top of the spring, hence the magazine is empty. (01:01:47)
Continuity mistake: When Dom and Brian are racing the train, the train numbers on the front of the train appear backwards. As soon as they cross the train, the train numbers appear forward: 3134. (01:37:22)
Continuity mistake: During the final hijacking scene, Dom pulls in front of the truck so Vince can get pull out the passenger side windshield with his harpoon gun. However, if you look closely right before Vince shoots his gun for the first time, you can see that the passenger side windshield is not even there. The glare coming off of the driver side windshield makes it very easy to see the difference between the two. (01:21:19)
Answer: There are two ideas of why the police did not come around. Firstly they might have found out after the car chase that Brian was an undercover cop so it would be more effective to allow him to try and discover information instead of going around and arresting Dom. The other idea is that the police might not have enough to arrest him. Dom was not the one driving when they found him and other than racing, it might be tough to arrest him.
Lummie ★
Cops are usually completely unaware of an undercover cop's identity. The more, realistic reason is that the cop didn't ID Dom and since Brian's car was later destroyed, there's nothing for them to investigate. Afterwards, they might ID Dom, but there's an investigation on him, so they'd leave him alone.