Plot hole: After escaping from execution, the assassins still made use of throwing knives out of their garments as they ran through the city. These would have been removed from them before they were shackled in the cell.
Continuity mistake: Immediately after giving the order to burn the village which hid the prince, the assassins attacked. In subsequent scenes, it appears that the village had already been burned to the ground, even though the guards were otherwise occupied, and only moments had passed.