There are lots of instances when the same people die over and over. When Robert is being chased on horseback, the same archer falls off the same horse, on the same corner twice. Also, during the siege of Camelot, the same archers fall off the battlements two or three times.
When they enter the deserted castle, the trees in the background have no leaves yet the next day all the trees in the woods are green from all the leaves.
At the end of the film, Queen Katherine is talking to Robert and, at one point, she turns around and the top part of her dress is obviously fastened with a zip.
The monarch's standard includes a quadrant with the Fleur De Lys: this relates to the monarchy's French possessions. However, this connection did not arise until 1066 when William of Normandy defeated Harold at the Battle of Hastings to become William 1, so the standard could not have been that of monarchs of Saxon times.