The broom that Arthur throws at Lancelot while Lancelot is sharpening swords has its head disappear entirely between Arthur throwing it and Lancelot catching it. The head instantly re-appears when the shot goes back to Lancelot holding the broom.
In the beginning, after the first "fight", Arthur puts his sword on the shield Merlin is carrying with the blade sticking out to the right (of Merlin).When the angle changes, the sword is in the middle with the blade to Merlin's left.