Factual error: In the final football game scenes ( from about three-quarters of the way through the film or so) all the spectators are wearing 1970's clothes and have 1970's hairstyles.
Plot hole: In the scene where Colby is discussing tactics with the team, Pele interrupts and takes the chalk from Colby and says "Hatch gives me the ball here, I do this, this, this, this, goal" while drawing a line on the blackboard to indicate dribbling from one end of the pitch to the other. At that point in the film, Hatch was only the trainer, not the goalkeeper.
Continuity mistake: Before the start of the match, the teams line up and acknowledges the spectators. In the number 7 shirt for the Allies is John Wark, yet at the start of the second half, the same player is wearing a red track suit and sitting on the reserves bench. At no point was he injured or replaced.
Plot hole: Hatch is told by the young boy that the escape is planned for half-time when they are already on the pitch. The senior Allied Officers in the crowd did not know this. When the team do not escape at half-time and return to the pitch, the Officers are shown to be surprised, even though they did not know the team was not planned to return.
Continuity mistake: At half time the POW team climb into a hole that leads to the tunnel and argue about going back. The tunnel has just had gallons of water flow through it from the bath, but the team come back all clean and their feet aren't even muddy.