Factual error: Peter and Lizzie play their semi-finals on the same day, but the men's semis are the day after the women's at Wimbledon (unless there has been significant rain, which there wasn't).
Factual error: Peter Colt's men's semi-final appears to take place on an outside rather than show (Centre or Number 1) court. This would only ever happen if there had been sustained rain, which didn't happen.
Factual error: Peter and Lizzie are shown driving out of London in the early evening summer sun to escape to Peter's home in Brighton. This is about half way through the film. There is a clear shot of the car driving west on the A4 out of town. As Brighton is directly south of London this is definitely not the way you'd drive. If you wanted to go to Brighton from central London you'd take the A23/M23 all the way.
Factual error: The box housing players' close friends and family is at 2 o'clock from the umpire's chair (in front and to the right). In the final, it is shown as being diametrically opposite (behind and to the left of the umpire).
Factual error: Men's final day is held on the second Sunday of Wimbledon. However, at 7am on the morning of Peter Colt's final appearance, we hear the radio greeting of Radio 1's Chris Moyles. Moyles is a weekday not weekend breakfast DJ. This would only be possible if the final were held over from Sunday to Monday because of sustained poor weather, which didn't happen.
Factual error: When the players walk out for the final, they walk up a long concrete tunnel. The entrance to Centre Court looks nothing like this – it's a well-kept room with a staircase, trophy cabinet, and a winner's board.