In his interview of Feisal, Jackson Bentley mentions that "certain influential men" in America want their country to join World War I. However, this conversation occurs after the fall of Aqaba, which was in July 1917; by that time, the US had already been in the war for several months.
When Allenby and Lawrence visit the officers' bar in Cairo, immediately after Allenby says "Shall we go outside?", a bright yellow American school bus is briefly visible driving by the distant window in the right-middle portion of the frame.
During the attack on Aqaba, a Turkish soldier is seen with a Browning M1919 machine gun. Which would not have been in use at the time of the Arabian revolt (1917) and it would not have been used by the Turks.
Following Lawrence's memorial service, the view of the front of St Paul's Cathedral shows that the left-hand clock face (the North) is missing. This was actually destroyed during the Second World War, which did not begin until 4 years after T.E. Lawrence died.
In the well scene when Lawrence and Ali first meet, Ali uses the water bag of the man he has just killed to hoist up some water, fill Lawrence's cup and drink from it. He then drops the water bag, which clearly falls behind the well and can be heard splashing on the ground, but that sound is immediately followed by a much louder dubbed sound of the water bag hitting the bottom of the well.
After the dissolution of the Arab Council, Ali disappears into the shadows leaving Auda alone by the reflecting pool. He looks briefly at the reflected moon in it, then turns toward camera as if to stare directly at it. But for the moon's reflection to be visible to the camera, the moon must be behind him.
General Sir Edmund Allenby (promoted to Field Marshal in 1919) is characterized in the film as being cynical, manipulative, obstructive, and dismissive of Lawrence and his Arab allies, and come into conflict with them several times. However, there is significant evidence that Allenby and Lawrence enjoyed working with one another and had a good relationship that stretched into the post-war period. Allenby even endorsed Lawrence's book, "Seven Pillars of Wisdom," while Lawrence remembered him fondly as "great." Allenby also appeared to respect the Arabs working alongside him, as evinced by his congratulating Prince Faisal on the "great achievement" of his "gallant troops."
As Lawrence approaches the Suez canal from the east, he hears then sees over a dune the ship traveling left to right, obviously north. When he goes atop the dune, the ship is trailing away to the south.
When Lawrence is crossing the desert with the prince's 50 men he starts to drift off. He is seen looking at his own shadow on the right side of the camel, but in the next shot the shadow is right under the camel. (See also Revealing Mistake)
When Col. Brighton and T.E. Lawrence are having a discussion after just having destroyed the train carrying some horses, the shadow on Col. Brighton's face changes from covering his entire face when both speakers are shown and the sun is behind him, to appearing only beneath the collar of his shirt when he is the only person in the frame.
As the Arab Army advances upon the Turkish rear, Lawrence and Ali look to their right at the thunder of the British artillery shelling the Turkish lines. Since in real life they were on the British right flank, they should have been looking to their left.
On their way to Wadi Rhum and Aqabah Lawrence and his party of 50 have to travel north and cross the Devil's Anvil. Yet, when Gasim is seen walking at sunrise he has the sun to his left and a stretched shadow to his right, meaning he is travelling south.
Lawrence rides his camel on beach at the Gulf of Aqaba, after the victory over the Turks. The audience sees big waves in the water coming at Lawrence. These waves signify tide. There is no tide in the Gulf of Aqaba. In this region the water is often is smooth and calm as a windless lake.
When Lawrence is being escorted across the desert on his way to Faisal's camp, his Bedu guide offers to share his food with him. Lawrence is somewhat reluctant but is anxious to show that, unlike other Brits, he is at one with the desert people. He reaches into the guide's proffered dish and takes a morsel - but with his left hand, and he does it twice. The Bedu shows no reaction, but he should: among the desert Bedouin tribes, who eat by hand, the left is kept away from the food as it is the hand with which they clean themselves after defecating. It could be that the guide is observing another Bedouin custom, that of warm hospitality and unstinting generosity to strangers, and is too polite to mention the gaffe (he would probably be aware that many outsiders do not know of the taboo), but it is more likely that it is a genuine error. Peter O'Toole is left-handed, and though he goes to great lengths throughout the rest of the movie to do things right-handedly (T.E. Lawrence was right-handed), this was probably a momentary lapse that no one noticed, or thought to mention.
Throughout the movie T.E. Lawrence is seen carrying a British Webley Mk. VI revolver. Though it was the correct weapon for British officers of the era, the real T.E. Lawrence had sent for two Colt M1911 pistols in 1914 when a friend was traveling in the US and British pistols were scarce due to the war effort. The M1911s would serve Lawrence as his personal weapons throughout his campaigns. In his letters to this brother he wrote: "The Colt is a lovely pistol. The more I examine it the more I like it. There is a vast gulf between it and the ordinary revolver."
At 1 hour 48m 56 seconds Auda Abu Tayi (Anthony Quinn) is smashing telegraphic equipment. In front of Auda Abu Tayi is a vacuum tube of approximately 1940 vintage and on the left hand side of the screen is a supethet radio receiver again of approximately 1940's vintage (with the tuning capacitor half open). Although vacuum tubes had previously been invented (1904) it is most unlikely that these would have been used in telegraphic equipment in Arabia in 1916. The Morse code heard when Auda Abu Tayi smashes the equipment is of an electronic nature again not available in 1916.
When Lawrence reaches the Suez Canal, a steam freighter passing through blows its whistle. The whistle is an electric siren whistle. In 1917 most merchant ships were steam-powered. The ships whistles would have also been steam powered and the whistle would have given out a bellowing sound, not a piercing shriek as from an electric whistle as seen in the film. A steam whistle would have also emitted a great, highly-visible jet of steam upon being used.
About 15 minutes into the film, Lawrence and Tafas are resting at night. The scene was filmed during the day with filters. The scene ends with a brief shot of the moon. The moon's top half appears illuminated which can only happen when the sun appears high in the sky.
When Lawrence issues the promissory note to Auda he writes right-to-left. Many have interpreted this as the film being processed backwards when in fact he is writing Arabic which is right-to-left. And when he signs his name at the bottom, he does so left-to-right.
Over the course of the film, several Ottoman Turkish soldiers are seen armed with British Short-Magazine Lee-Enfield (SMLE) No. 1 Mk. III rifles. Although it is indeed not a standard Turkish weapon, many Lee-Enfields had been captured during the Gallipoli campaign between 1915 and 1916 and from other battles. Several were then issued to Turkish troops, some after conversion to the standard 7.92mm Mauser ammunition used by the Turks. Their appearance in the hands of Turkish soldiers is, in this case, justified, though it remains true that the majority of the Turks would still be armed with Mauser rifles. The reason for their use in these scenes is most likely that Lee-Enfields were the rifles that the filmmakers could acquire with the least trouble, given their filming location in several former British colonies, and had been 'assigned' to stand in for Turkish weapons.
Further to the change of the shadow position during the "drifting" scene, this shot is of an apparent evening/dusk period where the shadow is almost directly under the camel, revealing it to be a "day-for-night" shot which must therefore have taken place near noon.
The goof item below may give away important plot points.
In the movie, Farraj is mortally wounded by a detonator going off in his clothes, but in The Seven Pillars of Wisdom, T.E. Lawrence writes that Farraj was wounded by a Turk shooting him while riding on his camel.