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)
Other mistake: When Cade is fighting Savoy, Cade jams his thumb deep into Savoy's right eye socket. A moment later Savoy is seen with no right eye injury.
Revealing mistake: When Galvatron is firing rockets on the Autobots, a flatbed truck swerves into the back of an RV causing it to flip over and explode. There is no driver in the RV. (01:17:40)
Visible crew/equipment: After Optimus stabs Lockdown and slices him in half with his sword, it cuts to a shot of Tessa witnessing it, and Shane getting out of the tow truck. When the camera pans towards Shane, he shouts "Yeah" and the reflection of a boom mic can be seen on the wing mirror of the tow truck just before the shot cuts. (02:33:20)
Revealing mistake: When Bumblebee drives up the KSI building, he swerves the car around to face the building and let Tessa and Shane out. The tyre marks are visible on the ground before he swerves the car, most likely from a previous take. (01:12:10)
Revealing mistake: When Bumblebee is transporting Joshua, his face is cut from another shot and placed on the one of Bee driving. This is obvious by the incorrect lighting on his face and lack of reaction to his surroundings.
Visible crew/equipment: In the final battle scene, just after Bumblebee temporarily knocks over Lockdown, Cade shouts "Get out of here, now" and it cuts to Tessa and Shane about to get into a tow truck and Shane telling Tessa to get in. In this shot, the reflection of a crew member, most likely a cameraman can be seen briefly reflected on the door of the tow truck. (02:31:40)
Continuity mistake: During the scene when the hunter's ship is picking up the Land Rover with the seed, Darcy falls out of the truck twice - once forward and once backward - one right after another. (02:25:32)
Visible crew/equipment: When the red car flips through the truck during first car chase after locating Optimus at the house, the first shot doesn't show anything there, then after the car flips through truck, a camera is shown on the ground, presumably filming but looks like they never used the shot. (00:41:53)
Continuity mistake: When the Autobots are reunited it shows Bee, Crosshairs and Drift in his Bugatti form all driving together, than all of a sudden Drift is up on the mountains and jumps off into his helicopter form. (00:52:29 - 00:52:56)
Continuity mistake: At the end you see Bumblebee driving in and in the far away shot you see him drift/stop in front of Cade and everyone but next shot you see him drive in again and transform.
Continuity mistake: When Darcy is at the site in the Arctic, the frozen Dinobots she sees do not appear until she walks up to them. In the establishing shot of the site, they are nowhere in sight. And in the shot where the site worker is pointing a shotgun at her, the only things seen in the background are the vehicles on the site. The frozen Dinobot suddenly appears in the background when she continues to walk towards it. (00:03:05)
Continuity mistake: When Cade is showing Tessa the photo of him and her mother, the right corner of the frame is shadowed compared to the rest of it. A few seconds later, when Tessa begins to walk away, the shadow in the right corner of the frame has disappeared. (00:23:05)
Continuity mistake: When Tessa is on Lockdown's ship, she comes across the Cemetery Wind team making the trade with Lockdown. In the shot shown of Tessa looking at them in the background, the helicopter that Cemetery Wind arrived in has its propeller spinning really fast. It then cuts to Savoy, where the propeller is moving much more slowly and about to stop. (01:27:30)
Continuity mistake: When Cade and Lucas are walking up to the theatre, in the shot where they are approaching the owner, he is shown leaning against his car and facing away from them. The shot then cuts to the owner, where he is suddenly facing towards them. (00:04:50)
Continuity mistake: When Tessa and Lucas are telling Cade they need to get the truck out of the barn, Cade says he's been working in there all night, and he is fine. His arms are raised when he says this, but when the shot cuts, his arms are suddenly by his side. (00:26:05)
Answer: Optimus was being dramatic when he said it contained their memories. Transformers don't carry their memories in their spark any more than humans carry theirs in their soul.
MasterOfAll