When the soldiers find Darius' chariot, there are dual cutting blades attached to the wheels. Seconds later, when the chariot is driven away, the blades are gone. Not enough time elapsed for the blades to be removed.
Many of the actors playing soldiers wear comically ill-fitting helmets, including the star's own. Burton's helmet never sits properly on his head and has fabric stuffed into the empty ear holes in a vain attempt to cover up the gaff. A simple session of "musical-helmets" amongst everyone could have solved the problem quickly and economically.