Blooper

When Sara is climbing the train trestle, there is a closeup of her boots slipping on the bracing. The next shot shows a view upward from underneath her and her boots are now black sneaker type shoes.

After Hogan's first shot at the dynamite under the trestle, the camera angle reverses to Sara, who takes the rifle, cocks it, hands it back to Hogan, and then re-sets it on her shoulder. When the camera returns to the trestle, the train hasn't moved.

When Hogan takes his last sip of whiskey before the arrow removal, he puts the bottle to his lips. In the next shot, he is already setting it on the ground.

When Sara and Hogan are hiding from the French soldiers in the abandoned building, Hogan's cheroot changes length inconsistently between shots.

Rattlesnakes shake their tails at up to 90 hz (faster than hummingbirds flap their wings). A person could not produce the characteristic warning sound by manually shaking a dead snake's tail.

When Hogan gets shot by the Yaqui arrow, the arrowhead is clearly shown sticking out of his back, then a minute later the next shot of Hogan's back shows that the arrow did not fully penetrate.

In the French HQ, when Hogan and Sara ask General LeClaire for champagne or cognac, he relays the order to his subordinate in English and not in French.

During the battle for the French headquarters, Hogan lights and throws a stick of dynamite with power and accuracy using his left hand, when a couple of days before his left shoulder was pierced by an arrow. He throws other sticks with his right hand after that.

Several days are enough for Hogan's shoulder to heal somewhat and for his pain to subside, combined with the adrenaline rush of participating in battle which would allow him to throw at least one stick of dynamite with his left arm.

Immediately after switching to the burro, Sara and Hogan arrive in a town along a dry creek bed. They dismount, and walk to their left up the bank, then cross a stone bridge over the creek to the market square. But they could have simply walked up the bank to the right, directly to the square.

They could have, but they didn't. Choosing to take a bridge instead of walking up the embankment is not a "goof".

The train trestle that is "blown up" is an open deck trestle that would be fully supported by the stone towers or "bents". The wooden bracing that Sara climbs would not be needed or serve any purpose other than to give her a way to climb, unless it is falsework left over from construction of the trestle, or unless it was deemed necessary during construction due to some flaw in the supporting structure of the open deck.

When Hogan returns from his lookout as he sees the advancing French soldiers, he scrambles down a hill toward a small stream. Visible through the trees is a modern highway railing.

When Beltran wakes Hogan in the cave, the Juarista sitting woodenly upright in the background wearing a sombrero is clearly a mannequin. It never moves, and its hands are positioned as if it's holding a box on its knees.

When Sara pushes the arrow through Hogan in order to remove it, there is a thin black wire attached to the tip of the arrow indicating it is being pulled to give the illusion it is being slammed through Hogan.

The tarantula at the end of the opening credits is obviously nailed to the ground.

The night that Hogan uses the gunpowder to make enough light to see a mountain lion, it's clearly daytime, with a filter on the camera. The sky is blue above the trees.

The French did not celebrate Bastille Day until July 14th, 1880.

The story takes place during the French intervention in Mexico from 1861 to 1867. Dynamite was invented in 1867 by Alfred Nobel, yet it was not easily available in the US until at least 1868.

In the tunnel scenes, Hogan and friends are using hand-held carbide lamps. Carbide was not produced in any quantity until 1892, and carbide lamps were not invented until several years later.

The story takes place during the French intervention in Mexico from 1861 to 1867. Hogan is using a Colt Peacemaker pistol, which did not come into use until 1873. The 1873 Winchester, 1874 Gras and 1907 Berti rifles, as well as the 1917 Colt New Service revolver were not in use at the time either.

The train locomotive has the headlight mounted in the center of the smokebox door, which was not common practice until the early 1900s.

When Sara encounters the rattlesnake and Hogan comes to her aid, there are some close-up shots of the snake and you can see the tail is being moved by a thin wire.

In the train trestle scene, in the moments prior to the dynamite explosion and resulting crash of the train, there are no wires/cables visible above the trestle. But when the train is seen approaching, wires or cables are clearly visible overhead.