After Dolworth (Lancaster) has set the fuse on the dynamite under the water tower, he returns and wades through knee-deep water. The next frame shows dry pants.
When the team makes it back to the train after capturing Mrs. Grant Claudia Cardinale and the ambush is waiting for them, Ehrengard Robert Ryan is initially shown from inside the train car sitting facing sideways to the open door of the train car, then from outside he is shown with his back to the door of the train, then back to inside and he is sideways again.
Ehregard (Ryan) was shot in the upper right shoulder. The blood stain is visible in several shots. However, as they separate from Dolworth (Lancaster) while he holds off Raza, it's very clear that Ehrengard's shirt is missing the blood stain.
Jake tells the others "Raza and six" are pursuing them, from his vantage point. But it's Raza and 7 instead. In his delaying action, Dolworth kills six of Raza's men, then has to kill Chiquita also, when she rides up and tries to shoot him--leaving Raza wounded but still alive.
During the shootout with the Mexican bandits in the canyon, Lee Marvin (Rico) started out with the shotgun, then drew his pistol to shoot at one of the bandits who was on the ground. After you see him point his pistol at the bandit, the camera then cuts to behind where the bandit was lying, and you can still see Lee Marvin shooting his shotgun.
At the beginning of the movie, Grant (Ralph Belamy) is told that his satchel contains $100,000 in gold coins, with "nothing larger than a $50 piece." The highest value gold coin issued by the US mint was only $20. Also, at the official rate of $21 per oz at the time, $100,000 in gold would weigh over 300 lbs. The banker and Belamy both handle the satchel one-handed.
Fardan uses a drawing compass to measure distance on the map. He does so by holding the legs. This is incorrect, as doing so could affect the spread. The correct way is to hold it by the peg at the top.
At the end of the scene when the gang are sitting on a ridge talking about battles and promises, Fardan exits the shot. Dolworth puts his cigar in his mouth and puts the binoculars to his eyes backwards, ocular lenses out.
As the Professionals escape in the mine cars, there is an overhead shot in which the cable pulling the cars is visible.
In the beginning credits, it's clear that the footage was run forward and then in reverse. The flames beneath the coffee pot, rise and then dip and then rise and dip again. The accompanying smoke also stops, retreats back into the flames and then comes up again.
Joe Grant states, while reading the biographies of the Professionals, that Fardan left Pancho Villa's forces in June 1915 and spent a year prospecting fruitlessly. Later, however, at the camp at the old church, after Dolworth states that he joined the Mexican revolution in 1911, Maria Grant states that no man was more loyal to the revolution than Fardan and that he and Dolworth stayed and fought for six years, implying that Fardan did not leave Villa until 1917. As Raza's lover and confidante, Maria should have known that Fardan (and Dolworth) were long gone from the revolution by 1917.
When Fardan (Lee Marvin) has the Dolworth (Lancaster) and Jake (Woody Strode) synchronize their watches at 4:30, Dolworth states that the fuse that will detonate the water tower at Raza's compound will take exactly a half hour. The time for the detonation is set for 5:00. However no time was taken into account to have him set the charge, which had to take at least a few minutes.
He had a half hour to set the charge, between 4:30 and 5:00. The actual dialogue is "I'll be ready by 5 o'clock. This fuse will burn for a half hour exactly. Fireworks start at 5:30 sharp." So the time set for detonation is 5:30, not 5:00.
He had a half hour to set the charge, between 4:30 and 5:00. The actual dialogue is "I'll be ready by 5 o'clock. This fuse will burn for a half hour exactly. Fireworks start at 5:30 sharp." So the time set for detonation is 5:30, not 5:00.
Incorrectly regarded as a mistake: Claudia Cardinale was Italian and her accent reflected her Latin roots, which included Castillian Spanish. During the years surrounding the Mexican Revolution, it was fashionable for upper-class women in the country to take diction lessons to make their accents more Castillian, as a way to separate themselves from Mexican Spanish, which was derided as the language of peasants. When Maria married Joe Grant, she almost certainly would have undergone similar diction training so she would stand out from the hired help. Thus, Cardinale's Italian accent was not out of place.
During the shootout in the canyon, Dolworth has Sharpe jump across into the opening with his hat raised to draw fire. The sound of a rifle shot follows. However, the stuntman playing the Mexican on the horse had trouble handling the animal and his rifle and missed his cue, so he appears after Strode had already done the distraction. Director Brooks added the gunshot to make up for the mistake.
At around the 1:40 mark, when Raza is calling for Francisco, a horse in the background is "doing a number two" while in the shot.
Near the end, in the canyon where Burt Lancaster is alone in a shootout, right after Jack Palance calls out for "Francisco" there's a scene of Francisco face down and the horse behind him can clearly be seen defecating.
As Grant's train pulls out of the station after Dolworth is picked up, one of his guards climbs aboard the platform car as it begins to move. The movie's third unit director decided it would be a good visual for the other three guards to leap on to the platform from the horse ramp. However, the first man hesitated, forcing the next two to hurriedly jump almost on top of each other. The second man stumbled but the third man fell flat on his face. As Director Brooks did not want to back up the train to re-shoot the scene, it was left in the movie.
Some of Raza's men are shown wearing shirts that button all the way down the front. These shirts did not come into common usage until the following decade after the film's setting and even then were too expensive for poor villagers or bandits to commonly wear.
Dolworth makes reference to the universe being created with a "big bang", but this theory was likely not known in 1916-18, being first noted by Georges Lemaître in 1927.
Fardan asks Jake how far he could shoot an arrow with a 4oz stick of dynamite taped to it. Masking tape was the first general purpose tape invented and that was not until 1925. In any event, in 1917 mercenaries did not travel through the hot desert with any kind of tape. the correct question would have asked about tying a stick of dynamite to an arrow, not taping it. It's unclear in the following scenes if tape or string were used to attach the dynamite to the arrows.
While Rico is shown to be a weapon's expert, unless he had spent some time in Europe prior to WWI or during the early portion of the conflict, there's no way he should have been familiar the French 75mm howitzer. The weapon was not commissioned until 1911 and its first wide-scale use was on the battlefields of Europe during the war.
The weapon was sold to the US; however that was later during the conflict and after WWI, thus after the setting of the film.
Mrs. Grant's hairdo is what would be worn by a woman in the 1960s, not the 1910s.
When the professionals attack Raza's fortress, some of the dynamite explosions are preceded by a flash of light before the actual explosion. Lack of synchrony in special effects.
During the scene where Burt Lancaster's character is holding Si Si Chiquita, he turns her over and she places her revolver at his neck and pulls the trigger. The cylinder moves as the hammer falls but the click isn't heard until the next shot (edited in)..
Just after Ehrengard is told to "say only what I tell you," Padilla's mouth moves, but no words come out.
When Maria, Dolworth, and Fardan are sitting around the campfire after she has treated Ehrengard's wound, Fardan is cleaning the open breech of his pump action shotgun. At one point in the scene he brings the gun to his shoulder and closes the bolt. But instead of just a "clack" sound, as would be the case from closing the bolt of such a weapon, a "clack clack" sound is heard. That sound comes when one operates a closed bolt back and forth, as when loading a round into the chamber. It would not happen from the single action of moving the bolt forward.
While it made for an exciting plot twist, having Raza catch up to the train and find it empty, it would have been almost impossible to pull off. Raza's people were trailing the train relentlessly and it's doubtful that five people (one of whom was badly wounded) would have been able to exit the train, along with their horse and all their supplies, without being noticed, especially while the train was moving.
The mules disappear after the canyon explosion.
Dolworth rides south down the narrow canyon, scouting ahead of Fardan and the others. He hears a horse from Raza's three-man search party farther south in the canyon. Dolworth hastily turns a cross upside-down in a grave, as a signal to Fardan, and continues riding south, where he is confronted by Raza's three men. Minutes later, Dolworth's team, riding south in the canyon, come upon the upside-down grave marker left by Dolworth. Jake examines the area for horse tracks and tells Fardan that he sees tracks from Dolworth's horse and three others (Raza's men). But Jake could not have seen horse tracks from Raza's men, since they were confronting Dolworth farther south in the canyon, and had not advanced that far north.
When they first meet ten of Raza's men in a narrow canyon, Jake spots them coming, from a high vantage point. Yet Dolworth warns, "They've got bolt-action rifles." How would he know? He didn't see it, and Jake didn't mention it.
J.W. Grant correctly pronounces the name of Pancho Villa as "VEE-yah," but then refers to Jesus Raza as "JEE-sus," instead of "Hay-ZEUS." If he knew enough about Spanish to pronounce Villa correctly, he should have known about Jesus.
After the massacre of the Mexican bandits in the canyon, Dolworth and Fardan proceed to dig graves for the 10 dead men in the sand. Removing loose-falling sand for one grave would be an arduous task, much less for burying 10 worthless villains, with no benefit to their posse whatsoever. And after the next 3 bandits (who hang Dalworth by his ankles) are killed, they don't seem compelled to bury any of them at all.