Maureen O'Hara wrote in her autobiography that the famous climactic spanking scene was completely authentic and that John Wayne carried it out with such gusto that she had bruises for a week.

John Wayne once remarked that, try as he might, he couldn't get Big John Hamilton to react properly in the scene where McLintock was "explaining" the rules for the fight between Fauntleroy and Dev at the party. Finally, Wayne resorted to actually stomping on Hamilton's foot and kicking him.

When John Wayne needed 500 longhorn steers for a key scene, the Mexican government lent them to him. Mexican longhorns' horns tip up, as opposed to American longhorns, whose horns tip down.

John Wayne insisted that the role of the weak, insipid Governor be called "Cuthbert H. Humphrey" with the intention that he be seen as a parody of liberal Sen. Hubert H. Humphrey, whom Wayne intensely disliked. Humphrey was Lyndon Johnson's Vice-President and the Democrat candidate in the 1968 Presidential election, losing to Republican, Richard Nixon.

According to producer/son Michael Wayne, in the scene where GW (John Wayne) jumps from a balcony to a pile of hay in a sitting position, Wayne thought it looked like fun and insisted on doing it himself, instead of a stuntman. Although studios frown on a valuable star doing a potentially dangerous stunt, Wayne eventually was allowed to do it, but it was also shot with a stuntman, just in case.

Continuity

After Katherine is covered with molasses and feathers, including her hair, during the Indian "attack," McLintock goes to see her five minutes later. She greets him with clean dry hair and skin, wearing a new corset, slip, etc. While she might have been able to change her garments in that time, there is no way she could have gotten molasses and feathers out of her hair or off of her hands.

During the fight between Dev and Ben, G.W. comes out carrying the whiskey. There is clearly a poorly repaired crack in the wall next to the door. Later, when Ben dives at Dev and misses, he runs into the wall, undamaged, and creates the crack that was there when G.W. walked out of the door earlier.

In the long fight scene at the end, Katherine flies out of a window and lands in a trough of water. After that, trying to escape G.W., she falls into the dusty and muddy road; but still, in the next scene her underwear are clean white - and dry.

The first man into the mud pit during the fight scene slides down the hill toward a brownish-reddish muddy water pit, then in closeup he slides into chalky gray water.

When Agard falls from his horse, his glasses are on his face at an angle. When getting lifted up, he has them in his left hand, but when he gets into the buckboard, they are back on his face at an angle again.



Factual errors

The greeting in Comanche is "maruawe," but the "Comanches" greet each other (and are greeted by McLintock) with "yatahe," which is a Navajo greeting.

G.W. suggests to Birnbaum that the solution to his chess problem is "queen's bishop to king 4." This is an impossible move, regardless of where the pieces are.

When GW and Drago drive the barouche into town early in the film, a line of poles lead from the house, across the road, and through a pasture parallel to the road after it curves. These are either electric poles or telephone poles, yet the house has neither electricity nor a telephone.



Revealing mistakes

When the band plays upon Becky's arrival, the music and the drums play but the drummer's beats are nowhere near hitting the drum. He misses by several inches.

In the store where McLintock chases Katherine, the part where he crashes into the baskets is very clearly done by stuntman Chuck Roberson and not by John Wayne.

When Devlin drives the buggy to take Matt home from the McLintock's with Becky, the scenery passes by much faster than a horse could possibly travel.

The band music being "played" for Becky's arrival has a clarinet in the score, but no woodwinds are shown in the group of musicians.

In the opening credits there is an artist's rendering of the town of McLintock, with signs for every building indicating that every business in town is owned by McLintock. The sign on one of the buildings misspells McLintock as "McClintock."



Miscellaneous

All the cans in the general store are clearly empty. The hollow sound of empty cans bouncing off each other and the floor is easily heard as the shelves are tipped during the brawl with Katherine.

McLintock and Katherine each have blue eyes, but their daughter Rebecca has brown eyes. Her eyes should be blue as well.



Anachronisms

In the mud fight scene, when John Wayne climbs out of the pit, a man is seen in the background wearing a modern grey business suit. In the same shot, there's also a person wearing sunglasses.

During the rodeo scene, one can clearly see a 48-star flag (6 rows x 8 columns) is shown. If this area is still a territory, it's not Alaska or Hawaii. Before Arizona and New Mexico became states, there were 46 stars.

When G.W. hunts, he reloads, but the shells he uses are plastic hulled, not the paper or the wax impregnated shells that would have been used during the time the movie is set. Plastic hulled shells were introduced by Remington in 1960. Remington used green plastic in their shells, so the movie was more than likely using modern Remington plastic hull shells.

During the rodeo, an evaporator cooler on the roof in the background is visible.



Audio/visual unsynchronized

When Junior Douglas sings with Becky at the McLintock house, he isn't really playing the instrument. His hand movements are completely out of rhythm with the music. Nevertheless, Jerry Van Dyke was an expert banjo player.



Crew or equipment visible

In the famous chase scene near the end of the movie, when Katherine tries to escape from G.W. into an alley behind the general store, the shadow of the camera as it zooms in for her close-up is clearly visible against the store wall on the left side of the shot.

During the fight at the mudslide, with Agard in the mining cart headed for the slide, the cable pulling the mining cart is clearly visible.



Errors in geography

The real-life "Mesa Verde" extends south into New Mexico (a territory at the time of the film), but scenes show saguaro cacti which grow only in the mid and southernmost part of Arizona and northwestern Mexico. Being a fictitious story, the "Mesa Verde" in the film may well be a fictitious place, as the precise location is never given. and allowable under artistic license. The term itself means "green table" and may have been used to describe any mesa with plant life on it. More likely, though, is that this story was filmed in Arizona because 1) there's a studio there (Old Tuscon Studios) and 2) to use the saguaro as a symbol of the old west, a common practice in Hollywood at the time.



Plot holes

Soon after explaining to Matt Douglas why he calls him only "Douglas" while calling McLintock "Mister McLintock," Sheriff Lord calls Matt Douglas "Mister Douglas."



Character error

Davey hangs the "Welcome Home" banner for Rebecca the wrong way. It can't be read from the approaching train or from the passenger platform, but only from the street looking back at the station. (In other words, only from the point of view of the camera, not the characters.)