Factual error: Immediately after the victory against the Soviets, coach Herb Brooks did indeed leave the bench and go back through the tunnel. However, it wasn't to find a secluded place to rejoice. He simply had to go to the restroom.
Factual error: In the actual Olympic games, the ice looked nowhere near as immaculate as it did in the movie. The movie's ice is pure white, with vibrantly-colored blue lines, red lines, etc. Anyone who has seen the actual footage of the game knows that the ice surface is blotchy, very much like a pond.
Factual error: Not every player at the Olympics wore Bauer skates.
Factual error: The skates are all modern - they are all black plastic, no metal.
Character mistake: While watching a documentary about the Soviet team Herb Brooks says that the Soviets had had 42 games in the last three months with 42 wins. This was supposed to be said in 1979. In the whole of 1979 Team USSR played 24 games only, winning 23 of them and losing Game 1 of the 1979 Challenge Cup, to the NHL All-Star team.
Factual error: Even though Jack O'Callahan was injured and couldn't play until the medal round, he still suited up for each game and skated during warm-ups. In the movie, he's wearing a suit and tie while on the bench.
Continuity mistake: After the coach's first argument with his wife, he returns to the bedroom to apologize. She's laying on her right hip and has to twist at the waist to see him standing in the doorway. He speaks, and the top of her head is in the shot the entire time. When the camera cuts back to her, she's now laying on her left hip, facing him square on. She couldn't have rolled over without causing her head to move or dip out of frame.
Other mistake: What are the odds that a small arena in Norway would use the exact same scoreboard as the arena in Lake Placid?
Factual error: The opening scene is set at USA Hockey headquarters, complete with logo out front and a receptionist answering the phone as "USA Hockey." However, the governing body now known as USA Hockey was then known as AHAUS (Amateur Hockey Association of the United States). AHAUS didn't become USA Hockey until 1989.
Continuity mistake: After Team USA beat Czechoslovakia, there's a scene on the streets of Lake Placid where Herb Brooks and his advisor are discussing why there is so much media covering the hockey team. Brooks makes the statement, "They've (USA) won two games." Actually at that point, they had won only one game, against the Czechs. They tied their first game vs. Sweden.
Factual error: The time clock digits on the scoreboard were not made up of individual round lights, as shown in the movie. They were made of illuminated bars, similar to the LED displays on alarm clocks.
Continuity mistake: At the skating pond, Herb's head is turned toward his wife as he says, "why can't we just leave it at that?" Right as he finishes that sentence, the camera cuts to a different angle and his head is instantaneously facing forward.
Factual error: The arena in the movie is way too small. The Olympic Ice Arena in Lake Placid had a capacity of about ten thousand, with an entire second level. The only "second level" the arena in the movie has is the small balcony at the end of the ice.
Factual error: Al Michaels never referred to the Harrington/Schneider/Pavelich line as the "Conehead" line when announcing the game on ABC.
Factual error: In the movie, after the USSR's first goal, the announcer *correctly* announces that the goal was scored by Krutov, who deflected the puck in. In the actual game, she incorrectly announced that it was the player who made the initial slap-shot. (Later in the game, Al Michaels pointed out the correction while doing the play-by-play.).
Continuity mistake: Herb's wife brings him a cup of hot chocolate at the outdoor skating rink. When she first gets there, both cups are steaming heavily. Just seconds later, neither cup shows even the slightest amount of steam coming out.
Factual error: Colorado Springs location shots are completely off. Broadmoor World Arena had a very high, arched roof, wooden seats throughout and no press box even vaguely resembling that shown in the film. It was demolished in 1995 though actual photos are still available here: http://www.coloradocollege.edu/athletics/hockey/history/allbroadmoor/BroadmoorWorldArenaPhotos1.cfm Olympic Training Center was built on the grounds of an old military base, no rolling hills or heavy vegetation. In 1979 the old barracks, used as dormatories for the athletes, were very prominent and visible on the grounds.
Continuity mistake: Seconds after the puck drop in the first Soviet game the ice appears to be used and worn out.
Character mistake: When Vladislav Tretiak was substituted by Vladimir Myshkin, Ken Dryden commented on this saying that Tretiak had been Tikhonov's bread and butter for a decade. Viktor Tikhonov became the Team USSR and Red Army Head Coach only in 1977, and he had never coached Tretiak on any level before.
Character mistake: Al Michaels, commenting on the Soviet team, remarks that some of the players had been playing together for the last 15 years. In fact, the eldest Soviet players, the Mikhailov-Petrov-Kharlamov line, started playing together in 1968, only 12 years before Lake Placid.
Answer: Since they all came from different, sometimes rival, universities, and thus had no commonality, he wanted to give them someone to dislike together, instead of fighting with one another. If they could all bond over what a bastard Brooks was, they'd come together faster as a team and have a chance of winning.