Trivia: If you listen very carefully to the part where Al MIchaels says, "Do you believe in miracles? YES...", you'll notice that it's from the original broadcast of the game in 1980. All other play-by-play was re-done by Michaels as the movie was produced. The reason they used the original 1980 broadcast for just that specific moment is that Michaels had a difficult time recreating the emotion and excitement he felt when shouting it as it really happened.
Trivia: During the "again" scene where coach Herb Brooks has assistant coach Craig Patrick repeatedly blow the whistle and the players skate back and forth, there was no acting involved. The scene took twelve hours each day for three days to shoot and the director wanted everything to be real so when the players are keeling over and out of breath, they really were out of breath.
Trivia: Members of the 1980 US Olympic hockey team paid a visit during filming, and described the experience as if being in a "time warp." They were moved by the sight of all the jerseys and amazed at the resemblance the actors had to their 1980 selves. In fact, throughout filming the actors were instructed to call each other by their movie name (whether the camera was rolling or not), so (for example), one actor would say, "Hey O.C.." and both the real Jack O'Callahan and the actor playing him would respond simultaneously.
Trivia: At the very end of the movie, while the narrator is talking about the events that followed the victory over the Soviet Union, the captain of the US team is shown standing on the top platform on the ice during the medal ceremony. Suddenly he motions to his teammates to come up and join him on the platform, and they all crowd together and are just barely able to fit. In light of this emotional moment for team USA, it was decided that at all Olympic Hockey medal ceremonies going forward, instead of having platforms big enough for just the captain, they would have platforms long enough so that the whole team can stand on each one. It has been this way ever since.
Trivia: The movie mentions the Challenge Cup, where the Soviet national team defeated the NHL all-stars 6-0. Believe it or not, it was the Soviet backup goaltender (Vladimir Myshkin) who played in that game. No wonder coach Tikanov had no reservations about replacing starting goaltender Vladislav Tretjak with Myshkin after the first period vs. team USA.
Trivia: If the US team would have only tied Finland in its gold-medal-winning game, it would have needed the Soviet victory over Sweden (later that same day) to still clinch the gold. When announcing the US-Finland game and explaining this scenario, Al Michaels called it "the ultimate irony," since the Americans would then be cheering the Soviets on to victory.
Trivia: During the final minutes of the big game, there is one shot in the movie where we see four US players skating backward into their own zone in an almost perfectly straight line. The exact same thing happened in the actual game. Bringing back four defenders forced the attacking USSR player to make a long shot from behind the blue line that Craig had no problem saving.
Trivia: When Jim Craig said to Coach Brooks, "Nobody understands your stupid sayings," he was referring to a notebook that the players kept, where they listed all of the unique things Brooks said. They called his sayings "Brooksisms." Some examples: "This isn't weaving for weaving's sake."; "You don't have enough talent to win on talent alone." and, "You're playing worse every day, and today you're playing like it's next month."
Trivia: At the Christmas party, backup goaltender Steve Janaszak has a towel around his neck (he always wore one when in uniform & on the bench), even though everyone is in street clothes. This decision was made probably to distinguish him from Ralph Cox, who had a similar handlebar moustache.
Trivia: The first scene that the hockey players shot with Kurt Russell was outside the bus, where four of the players tried to get Coach Brooks (Russell) to send Tim Harrer home. The director thought that since this would be the first time the boys interacted with Russell, there would be some genuine looks of awe and/or intimidation.