The scene in which Mackintosh enters the funeral, takes a pin from his lapel, and stabs Casey in the hand to see if he's really dead, echoes a similar scene in Charade (which is also about three ex-soldiers trying to get their hands on a bunch of gold bars that they attempted to steal years earlier. The romantic couple/spies in the church observing the sequence in shock here are Chuck and Sarah, with similar roles played by Audrey Hepburn and Cary Grant in "Charade.").