Visible crew/equipment: In the scene where the knights are attacked by the killer rabbit outside the cave, you can see the boom mic at the top of the frame.
Continuity mistake: When King Arthur is fighting the Black Knight, there is a fire behind the Black Knight that is lit in some shots and nearly out in others. (00:15:55)
Continuity mistake: In the scene where Sir Galahad is about to enter Castle Anthrax, it's pouring like there's no tomorrow. Although when he falls against the door and is about to open there is no rain, and no Niagara Falls pouring down the door. As a matter of fact, it's pretty dry on the door and almost a completely clear sky.
Revealing mistake: When King Arthur is fighting the Black Knight, when he is about to chop off his last leg we can see the Black Knight jump slightly, after he has done this we can see his leg fall before King Arthur has touched it with his sword. (00:15:25)
Visible crew/equipment: In the scene when the knights are fleeing from Castle Anthrax, there is a crew member visible on the left side of the screen, just when they hurry along the outside wall from the castle. (00:41:19)
Revealing mistake: In the scene with the French taunting they attack the castle. Shortly afterwards they run away and hide on the hill slope. When Arthur is trying to lie down he nearly guts one of the knights with his sword and just after that when he gets his sword in front of him you can see that it is a fake wobbly sword. (00:27:54)
Audio problem: Robin's minstrel's hand doesn't hit his tambourine the first time we hear them sing.
Continuity mistake: When the rabbit kills the first knight that is sent to kill it, the rabbit gets blood all over its mouth. However, when the knights charge the rabbit, in the shot of the rabbit watching them, the blood has disappeared. It reappears in the shots where it is slaughtering the other knights.
Continuity mistake: After Sir Lancelot has gone on a rampage at the wedding party, the bride is first seen with a clean face. Then in the close-up she has loads of bright red Pythonesque blood coming from her mouth and running onto her chin. In the next shot, the blood has disappeared again.
Continuity mistake: When the knights have built the rabbit and given it to the French they hide behind the top of the hill with woodland behind them. Then when they rabbit is launched at the you see a shot of them running uphill through clear ground.
Revealing mistake: The side of the beard of the three-headed knight's left head (their right) comes off just before we see that Robin has run off.
Continuity mistake: When the Green Knight is charging at the Black Knight with the axe, there is a shield leaning against the tree behind him. Then in the shot right before King Arthur cuts off the Black Knight's first arm, the shield disappears.
Revealing mistake: After King Arthur cuts off both the Black Knight's arms and both his legs, as Arthur rides away and the Knight is struggling on the ground, as he turns sideways you can see both his hands, held behind his back, and the depression in the ground where he is standing in a hole. This is how the effect was achieved.
Revealing mistake: When the black Knight is sitting on the ground with no arms or legs, the ground right next to him bends down, indicating his legs were buried.
Other mistake: It's revealed that the Knights who say Ni can't say "it" (at least, after they become the Knights Who Say... that other thing), but they still say "it," most notably when they're telling Arthur to place the second shrubbery next to the first one - "When you have found another shrubbery, you must place IT here, beside this shrubbery..."
Suggested correction: They aren't the Knights Who Can't Say "It" - they are the knights who are determined to be a pain in the **** regardless. They are going to be as big a nuisance as they can to anyone who comes along and pretending they can't say "it" is just their latest tactic.
Audio problem: At the beginning of "The Tale of Lancelot", Prince Herbert gazes at the curtain and asks, "What, the curtains?" but his lips don't move.
Continuity mistake: When Brother Maynard is reading the inscriptions on the wall Sir Robin is hiding behind Sir Lancelot, but whenever there is a shot from behind the group Sir Robin disappears.
Continuity mistake: When King Arthur and his knights go to fight the killer rabbit and then run away, Sir Galahad left his shield behind, but one second later when they're regrouping, he has it again.
Revealing mistake: When the Black Knight kills the other knight by throwing a sword through his head, you can see that the blood is coming from the sword, not the wound itself. Likely the actor had a blood tube in his hand, and let the blood run down the sword and splatter onto his face.
Revealing mistake: During the bit where the Knights are attacking the killer rabbit, in a few shots, most noticeable in an over-head view, you can see the wire that pulls the rabbit puppet along.
