Continuity mistake: The fan who came out onto the ice and draped a flag around Jim Craig's shoulders (a cameo by the film's director, by the way) put it on upside-down. The camera cuts away, then cuts back, and it's suddenly right-side up.
Continuity mistake: There is a scene during the training camp in which we see a manager of the team crossing off players names with a blue pen. We can see him crossing the same name off twice in different shots.
Continuity mistake: During the game against the Soviet Union, the US team ties up the score at 3-3. As Al Michaels comments on the tied score the crowd is panned and the scoreboard reads 4-3, which actually happens a few minutes later in the game. The digits are hard to read, but if you look closely enough, the mistake is detectable.
Continuity mistake: During the series of sprints that the coach makes the players do after the game against Norway, the number of players on the ice changes. This is especially evident during the first one they do in the dark (only about 16 or 17 skaters are shown instead of the original 21).
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.
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.
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.
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.
Continuity mistake: Seconds after the puck drop in the first Soviet game the ice appears to be used and worn out.
Chosen answer: The "Coneheads" (John Harrington, Mark Pavelich and Buzz Schneider) all were from the same area in Minnesota. Naturally, they gravitated together and would often be found working on plays around orange pylon cones at the end of the rink - hence the "Coneheads" nickname.