Sixteen minutes into the program, Doug drops a torch in the center of a line of gun powder but the ignition point begins at the lower right of the screen.
When the young chief is about to pick up the golden mask, he first bumps it with his hand and it wobbles a short distance across the table on its "stone" base, revealing that it has nowhere near the weight of real gold and stone.
The Tunnel appears to be extremely long, stretching off to a vanishing point. But as Castillano carries the golden mask out of the Tunnel, his shadow on the back wall reveals that it is only perhaps 30 feet deep, with the back wall painted to look like a tunnel receding to "infinity".
The Time Tunnel supposedly freezes Tony and Doug in time, along with the young chief and the Spaniards in the cave - but while they all hold their poses, the torch flames continue to flicker.
The sword Tony holds on Cortez is a 19th century U.S. Navy cutlass.
When Castillano first grabs the guards pistol he fire a shot in the air. There is no sound effect edited in and so there is no sound of gun fire.
(at around 13 mins) When Cortes has his ships burned you can see the man who set the ships on fire exiting the set pool, and you can tell the ships are models.
Cortes is depicted fighting in Veracruz against the Tlaxcaltecs but the natives living there were the Totonacs. The Tlaxcaltecs lived in the central zone of México, not in the Gulf Coast.
Saguaro cactus does not grow anywhere near Veracruz.