Visible crew/equipment: Just after Lockdown stabs Optimus in the chest with his own sword, Cade runs closer and shoots at Lockdown. He then hides behind some bricks. In that shot, the bricks are a broken wall that is two separate pieces. Then it cuts to a different shot as Lockdown returns fire at Cade, and now the wall is one piece. Not only this, but some random guy suddenly appears in the shot next to the wall and right where the explosion happens where Lockdown shot the wall. He is wearing the same color clothes as the wall and only visible for a moment. There was no other guy present until that moment and he just suddenly appears behind Cade and gets hit. It's presumably a special effects member setting off the charge in the wall by the looks of it and it detonated before he got out of the shot. (02:30:55)
Visible crew/equipment: During the scene where Cade and the rest are running for their life on the roof of the huge apartment building, when the Decepticons are shooting at them, the long shot of them running shows a few crew members crouching against a wall and a camera and also another crew member crouching down in the brick doorway.
Factual error: The elevator Cade leaves because there's "too much weight" shows in the next scene a weight limit of 680kg. Even if the four passengers weighed 90kg each (a total of 360kg) it would mean the seed weighed more than 320kg (over 700lb), which would mean that Joyce would never be able to carry it alone as he did several times.
Visible crew/equipment: During the finale battle with Lockdown when Shane is driving the truck, you can see the shadow from the filming Go pro on the wheel of the truck. (02:32:35)
Other mistake: During the introduction of Attinger, he is holding cards of the Autobots explaining what happened to them. One such card is of Ironhide, listed as last seen in Chicago. Ironhide was killed in Washington DC at NEST headquarters by Sentinel Prime in Transformers: Dark of the Moon. He didn't even participate in the Chicago battle.
Continuity mistake: In the scene where Optimus frees the "Legendary Warriors", aka Dinobots, they walk into the canyon area and Optimus addresses them and asks for their help. It appears there are 3, maybe 4 large robots. When Grimlock screams and starts to fight Optimus, the others disappear. They continue to fight, showing from wide angles, and the others are still nowhere to be seen. Grimlock then transforms and charges at Optimus, with nothing behind him or between the two. When Optimus knocks him to the ground, it shows the angle that he falls to the ground in slow motion, and the other warriors appear in the area that Grimlock just ran through.
Continuity mistake: When Bumblebee and Drift reach KSI headquarters a Rolls Royce is in the shot. In the next shot when Bumblebee is transforming the Rolls Royce is far away from Bumblebee. In the next shot when Bumblebee is crashed through KSI headquarters there is no Rolls Royce parked out front.
Continuity mistake: Optimus and the car Tessa is trapped in are caught in a net and are pulled up to Lockdown's ship. Cade then jumps and grabs onto the net whilst it is being raised. There is a brief moment where Optimus is not visible inside the from the net, before being visible again in the next shot. The CG artists likely forgot to add Optimus into the shot during post-production. (01:22:35)
Revealing mistake: When Tessa and Shane are trying to free Optimus from being impaled to the wall after he is stabbed with his sword, there is a shot of Tessa running towards Optimus after she grabs the hook belonging to the tow truck. In the background of the shot, the Willis Tower, also known as the Sears Tower, can be seen in the far background. The buildings surrounding the tower can also be seen as well. The Willis Tower is located in Chicago, but the scene is set in Hong Kong. The scene was likely filmed in Chicago. (02:32:40)
Continuity mistake: Cade says that this is a no dating household, that he doesn't date and neither does Tessa. Tessa then says that maybe he should, and storms off outside. Cade follows her, and as you see him leaving the shack, there is nothing in his hands. But when he gets outside and catches up to her, suddenly he is holding a power drill in one hand, and an adjustable wrench in the other. (00:23:15)
Continuity mistake: In the scene where the Autobots are escaping from the KSI building, closely pursued by Galvatron and Stinger, the satellite tracker used by Joshua to track them, using an orange false image view, indicates they are driving on a freeway leaving the city. This is backed up by a swooping shot showing the same. However a second or two later and they are in the middle of an open countryside, not a building in sight (there are many 360 degree camera sweeps), a few bridges and other cars, but also old concrete banked curves. This is on a test track which for some reason they didn't CGI to make it fit with the supposed scenery the satellite indicated they were near.
Factual error: Darcy tells Joshua Joyce about the meteorite that caused the dinosaurs to become extinct; she mentions that the piece of metal in question has been carbon dated to 65,000,000 BC. Carbon dating is limited to around 40,000 years. For longer time periods potassium-argon dating or other techniques are used. Additionally, carbon dating is used for life forms, not for metal. (00:58:45)