The establishing shot of the airport terminal, in the scene where Guy arrives, is not from a Canadian Airport. It is actually Terminal 2 of the Amsterdam Airport Schiphol in The Netherlands.
Warsaw (Poland) is played by Budapest (Hungary).
When Crunch tells Nicky that Francie is his apprentice, Nicky makes a comment about Crunch being a wizard. Jay Baruchel, who plays Francie, starred as a wizard's apprentice in The Sorcerer's Apprentice (2010).
When Francie (disguised as Amish) is transporting Crunch and Nicky across the Canadian border, he says to the border patrol agent that he is in a play, "Witness, the musical. With an exclamation mark." This is a reference to Witness (1985), a neo-noir crime thriller starring Harrison Ford and centered around an Amish family.
Jason Jones's wife Samantha Bee and Chris Diamantopoulos's brother Gus lived next door to each other in the same downtown Toronto building.