Trivia: The Sator Square dates back to Pompeii and is a square of 5 Latin words making a palindrome: Sator, Arepo, Tenet, Opera, and Rotas. Whichever orientation the square is in the words line up in both directions. Each word features in the film - Kenneth Branagh's character is named Sator, the forger mentioned near the start is Arepo, the title is of course Tenet, the opening sequence takes place in an Opera, and the Ukranian special forces who arrive in that sequence have badges on their arms with "Rotas" on them.
Visible crew/equipment: After exiting the turnstile, Sator looks through the window separating the two rooms and watches his past self interrogating the Protagonist in the opposite room. In the shot where his past self is shown hitting the Protagonist across the head with his gun (in reverse), the wheels of the camera dolly can be seen reflected in the window to the left of shot. (01:24:45)
Continuity mistake: While Kat is seated on her bed on board of the yacht in her bedroom and then Sator comes in to throw her a pillow, this one bounces on the bed and falls on the floor. After two shots, the pillow is inexplicably on the bed above two other pillows next to Kat. (01:03:48)
Visible crew/equipment: After going through the turnstile in Oslo, the Protagonist walks up to an ambulance, knocks out the driver and steals it. When he begins to drive off, the shadow of a huge stage light can be seen cast on the side of the ambulance. (01:44:34)
Visible crew/equipment: When Mahir and his partner get on the plane, and they put the guards to sleep with chloroform on the face in the scene of the crash, the shadow of the camera entering the aircraft can be seen on the right side of the screen next to the airplane's entrance. (00:39:27)
Continuity mistake: In the highway chase scene where Sator reaches the Protagonist threatening to shoot Kat if he doesn't give him the case with the Plutonium-241, he lowers the window, but when he's watching the inverted car overturned which is going to get up and move backwards, the window is closed. Then when he's going to give the case to Sator, the window is lowered again. (01:19:52)
Visible crew/equipment: When the Protagonist passes through Sator's turnstile to return to the ambush site on the highway and gets in the inverted car, a cameraman holding the camera is reflected on the wing mirror. (01:31:38)
Visible crew/equipment: When the Protagonist and Neil are in front of the turnstile at the freeport, and they notice the bullet holes on the glass, a cameraman can be slightly seen reflected on it behind the Protagonist just a moment before he tells Neil to not touch the holes.
Continuity mistake: When the Protagonist gives the case to Sator in the car chase sequence, and he and his men exit from the Audi and get on the other car, Audi's window is first slightly lowered and then up in two different shots.
Continuity mistake: When the Protagonist fights against the inverted man inside the freeport just after the plane crash, at a certain point the inverted man kicks the gun away, making it fall. The gun in the background changes position and distance in two different shots.
Continuity mistake: When Sator is on the highway looking for the Plutonium-241, he's seen coming out from the car and then closing the door, but after he checks in the BMW's glove box and returns to his car, the car door is open without anyone touching it. (01:31:58 - 01:32:49)
Continuity mistake: At the opera siege in Kiev, one of the terrorists in the background is shot and downed. Two seconds later, in a different shot, he is still standing and being killed again. (00:04:14)
Continuity mistake: When the Protagonist inverts himself and gets into the Saab - which is the car that overturned in the previous chase scene on the highway - you can see the car's tires resting first on branch lines' tracks, but in the next shot the tracks are gone and the ground is dusty. (01:31:41)
Continuity mistake: Just after the interrogation has been shown from Sator's perspective, it cuts back to the Protagonist and the other soldiers in the present. There is a shot of a medic looking over Kat, where his left hand is shown placing his gun on the ground. It then cuts to a different angle where his left hand is now placed over Kat's stomach. (01:25:41)
Continuity mistake: When Sator is in the blue room after walking through the turnstile, he picks up Kat, puts her against the window, counts down from three to one and shoots her. Whilst he is counting down, he has his hand on Kat's shoulder. The camera then changes to a different angle where his hand is now on Kat's upper arm, and then moves onto her shoulder. Sator then pulls Kat away from the window with his hand on her upper arm. (01:24:58)
Continuity mistake: When the protagonist is at Priya's terrace after menacing her husband, the position of her hands is not continuous between shots. (00:22:35)
Continuity mistake: In Stalsk-12, Wheeler and a blue team soldier take cover inside a house in which chunks of rubble have been blown out of the wall. When the pieces of rubble begin to reassemble back into the wall, Wheeler runs out and the soldier attempts to run out but gets sealed back in. Right after Wheeler runs out of the hole, and the soldier begins screaming, he is shown standing upright. But in the next shot, right before the rubble chunks go back into the wall, the soldier can be seen now kneeling over the hole in the wall. (02:05:45)
Continuity mistake: Just after the Protagonist has shot Priya, Kat is shown closing her phone after using it. Behind her, a man and woman are shown walking past on the sidewalk, and then after that, two women are shown walking past. In the next shot, these people suddenly disappear from the sidewalk completely. (02:23:56)
Continuity mistake: Whilst Wheeler is explaining the rules of inversion to the Protagonist shortly before he goes outside, as she is saying "Gravity will feel normal but appear reversed for the world around you", she is shown holding a small tank of oxygen in her left hand and begins attaching it to a tube shown in her right hand. The camera then changes angles and the oxygen tank is now in her right hand and the tube is suddenly attached to the tank. (01:30:02)
Continuity mistake: When the Protagonist is being dragged into the Freeport by two of Sator's bodyguards, an inverted Sator is in the background, dragging Kat by her arm on the opposite side of the gate. A closer shot of Sator dragging Kat is then shown, where he now has his arm across her abdomen. (01:22:10)
Suggested correction: People doing procedures change gloves all the time. There is nothing suspicious about using 2 pairs of gloves in 3 minutes.
He was already done with the procedure when he removed the first pair of gloves. He was never shown putting on the second pair.
It's the same scene replayed, a true editing error.
But this scenes are within about 15 seconds of time - so there is no time to put on another pair.