Factual error: One of the Spanish soldiers lights a torch with what appears to be a hand-held lighter. Early lighters were converted flintlock pistols (not yet invented during the time of this episode) and the earliest hand-held lighter would not be invented until three hundred years after this episode's timeline.
Revealing mistake: After the first Native American is shot in the back with the crossbow, the base used to stabilize the arrow in the back of the actor is visible underneath his clothing.
Revealing mistake: When Doug drops the torch on the gunpowder trail, the ignition of the powder is about one foot before the point where the torch is dropped.
Continuity mistake: In the opening scene of Doug and Tony's landing, Doug lands in a bush, but the next shot of the two recovering has Doug outside the bush.
Continuity mistake: After Doug drops the torch on the gunpowder trail, one of Cortez's men grabs and moves the powder keg out of the way twice.
Revealing mistake: The heavy stone table the mask is sitting on in the cave during the fight scene wobbles when bumped by the cast members.
Revealing mistake: The crossbow a Spaniard uses to shoot the elderly Indian is not loaded with an arrow.