Most if not all movies have that disclaimer at the end saying everything in it is fiction. Cop Land has a very specific disclaimer: as the film's opening narration explains, NYPD cops have to live in the city...with the exception of transit cops, so that most of the cops we meet in this film worked overtime in transit simply in order to take advantage of this loophole and live in New Jersey (in the fictional small town of Garrison). The ending disclaimer, however, adds that the film is fiction because no such loophole exists, or at least existed in 1997, for transit cops.
It's a "ledger fact," a useful term I learned from writer John Rogers of the clever, pulpy TV show Leverage. Rogers explained "ledger facts" as details which make sense in the context of a story, but are in fact completely made up. In the episode "The Bank Shot Job," Beth Riesgraf's character Parker needs to break into an old bank building and says she'll do it through "the ledger drop." She explains that banks built before computerized banking, like the one in the episode, had a "ledger drop" in the side of the buildings where local businessmen could drop off their ledgers at the end of the workday, showing what they'd earned. Ledger drops don't exist, but in that story they make sense. The episode has that detail because Parker needs a crawl space to crawl through, and — surprise — air ducts or anything else you see people crawling through in action stories are really too narrow and/or too flimsy to hold people. (Die Hard lied!)
Ledger facts, Rogers also explained, are paired with "black box facts": details that seem made-up but are true. They're named for airplanes' black boxes, which are in fact brightly colored instead of being black. The practical reason is to make them easier to find in the awful aftermath of a plane crash, so the crash's cause can be determined. (A black box was a plot element of "The Mile-High Job," an episode that involves an emergency landing of a jumbo jet on that bridge-highway that runs to Key West, so, Leverage wasn't trying to be realistic with that.)
Stories can make enough sense. They don't have to be completely logically worked-out, and in fact most aren't. YOU'RE ALLOWED TO MAKE STUFF UP. But it helps for even the fake stuff to make sense.