Fire sprinkler system
There is a scene where Gavin purposely sets off a fire sprinkler head in the ceiling of what looks to be his firm's break room. This causes every sprinkler in the office to turn on and water down the furniture and file cabinets, resulting in the evacuation of the office so that Gavin can remove a file without being detected. Only problem is -- if one sprinkler head is activated that does not set off all of the sprinklers in the next room.
Below is a paragraph found at: http://home.howstuffworks.com/home-improvement/household-safety/fire/f ire-sprinker-system.htm that explains how those systems work.
"You've probably seen a number of movies where a small amount of smoke triggers all of the sprinklers in a building, soaking everyone and everything inside. But did you know that sprinklers aren't even triggered by smoke, and they don't all go off at once? Fire sprinkler systems are actually heat activated, one sprinkler head at a time, and most fires usually require only one or two sprinklers to be extinguished. These are just two of the many misconceptions about fire sprinkler systems."
Including that scene in a serious movie, as opposed to one like Con Air where a large troop transport plane lands on a busy Las Vegas street, detracts from the overall believability of the movie. It's a way for a lazy acreenwriter to allow a character to achieve an end with an event that is impossible.
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Another more believable but also annoying scene is when the wheel comes off Gavin's car and it takes a long time for the car to come to a stop. I'm guessing the car is traveling about 45 MPH (~66 ft/sec) on the bridge when the loosened bolts cause the front left wheel to fall off and the brake drum takes the weight of that end. It would not take several hundred feet to come to a stop. I also doubt that the wheel would go off in its own direction. What is more likely to happen is that the wheel would stay inside the wheel well once the wheel comes loose.
You might disagree and say that the screenwriter or director used "dramatic license" but I call it a gratuitous scene to inject some action into the movie.