Continuity mistake: During the first fight scene in the castle, the fourth guard to die charges through the castle door and is killed by Robin Hood. The shot cuts and the guard is immediately followed by Sir Guy, but in between those two shots an arrow suddenly appears in the door which wasn't there before.
Continuity mistake: During the first fight the fourth guard Robin Hood kills is the one who charges through the castle door. This guard is shot right in the heart causing him to clutch were the arrow is protruding from his heart as he dies with first his left hand and then his right hand on top of his left after he drops his sword. He then fall forwards, his body coming to rest face down, still clutching the arrow with both hands after it becomes still. But in the next scene his body is laying on his back facing up he is still clutching the arrow with his right hand but his left hand is laying by his side. Even if one of other guards had rolled him over it should have been his right hand that would have fallen off first, because it was on top of his left hand.