Goof (errors made by characters, possibly deliberate errors by the filmmakers): One of the Canadian firefighters accepts the apology from Mouch and Otis on behalf of "the Commonwealth of Canada". While Canada is part of the BRITISH Commonwealth of Nations, the country is referred to as the DOMINION of Canada by its citizens.
Goof (factual errors): Larry tells Herrmann that their father was in Boston selling merchandise to Filene's Basement, a store chain that went out of business on December 29, 2011.
Goof (factual errors): Eigenberg's brother says that their father went to Boston to try to do some business with Filene's Basement. That store is no longer in business.
Goof (errors made by characters, possibly deliberate errors by the filmmakers): Tara suggests Severeid make an Alford plea regarding her complaint against him, saying it is an "apology on the record". First, an Alford plea is made in a court of law, not before an administrative board. Second, the plea is not an apology on the record. It's a plea of guilty in which the defendant asserts his innocence but acknowledges that enough evidence exists to make a guilty verdict likely.
Goof (factual errors): Detective Dawson describes the murder weapon as a ".45 caliber, Marine standard issue sidearm." Since 1985, the USMC standard issue sidearm has been the Beretta M9, 9mm, semiautomatic pistol.