Other mistake: When Squad 51 is on scene at the drowning incident, the victim's wife is wearing very unusual rings. One ring has a jumbo orange ball, another has a large cluster of small gold balls, and the third has large black and white pearls. Later, when the models are at the station they are wearing identical rings as seen in the previous scene, Suzanne is wearing two of the prop rings and Kathy is wearing the pearl ring.
Other mistake: During the rescue at the studio, when Roy tells Marco and Chet that they need to latch up the wagon before it pulls the stuntman over the falls, we hear the dispatcher say, "Copter 10, respond with Engine 69," but the subtitles read, "Trucker 10, respond..." There is no such thing as Trucker 10. Subtitles from Universal Studios 2010 DVD.
Other mistake: When Squad 51 is dispatched to the movie studio, while en route in the interior shot, in the rear-view mirror we see the reflection of the driver's helmet, and it has an 18 on it, instead of 51.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy