Factual error: In the original Transformers, Tyrese Gibson's character is credited as and wears the rank insignia of a USAF Technical Sergeant. In Revenge of the Fallen, set two years later, Gibson's character now wears the insignia of a USAF Chief Master Sergeant, three ranks higher than his rank in the first movie. The USAF would not jump someone three grades into the top 1% of the enlisted force no matter what his heroics or experience (that does not even happen to Medal of Honor awardees). Clearly the screenwriters recognized this as Captain Lennox is bumped only one grade to Major despite his actions in the first film and Gibson's character, as noted in another mistake, is credited as Master Sergeant Epps, a reasonable promotion. The costume department simply got the insignia wrong.
Factual error: The team go to the Smithsonian Air and Space Museum's Stephen F. Udvar-Hazy Center, which is located adjacent to Dulles Airport in Virginia - surrounded by rolling green hills - to find a Transformer. When Jetfire breaks out of the museum, beyond the broken door is a large, desert airplane graveyard with large mountains in the background. This appears to be the 309th Aerospace Maintenance and Regeneration Group (309 AMARG), a well known aircraft 'boneyard', located at Davis-Monthan AFB, in Arizona.
Factual error: In the scene where Galloway parachutes out of a C-17, Major Lennox asks Galloway if he is "familiar with the standard MC-4" parachute as he is helping Galloway don said parachute. The parachute that actually deploys when Galloway pulls the ripcord is not an MC-4, as MC-4 parachutes have rectangular canopies (shown correctly later in the film as the NEST team descends into the desert).
Factual error: When Jetfire uses the "space bridge" to instantaneously move the characters from Washington, D.C. to the Middle East (on the other side of the planet), it was still daylight. 7:30 p.m. (summer closing hours at the museum) in D.C. is 2:30am where they arrived, but it was still broad daylight.
Factual error: When Sam, Mikaela, Simmons and Leo are at the border crossing, the flag that is flying is that of Tajikistan, and they were supposedly transported to Egypt. Tajikistan doesn't border either Egypt or Jordan, the two countries that were mentioned. However, the insignia on the berets the soldiers were wearing match that of the Egyptian flag.
Factual error: When the Decepticons are reviving Megatron, General Morshower states something like "coming up from 9,000 fathoms". 9,000 fathoms is approximately 16,000 meters. The Laurentian Abyss, where it was stated in the first movie that Megatron was dropped, is around 6,000 meters deep.
Factual error: Right after the title the location moves to Shanghai, China and you see a train of a few oxide-red hoppers. One of them is lettered for the Missouri Pacific railroad, with the Mo-Pac eagle logo visible. Another hopper is lettered for Conrail. These American train cars would not be in China.
Factual error: During the credits, Tyrese Gibson's character is listed as USAF Master Sergeant Epps. However, throughout the whole movie, Gibson is seen wearing the sleeve chevrons of a CHIEF Master Sergeant. Chief Master Sergeant is the highest rank an enlisted person can hold and is NEVER referred to either verbally or in writing as Master Sergeant. Master Sergeant is a different (lower) rank.
Factual error: Mikaela hotwires the silver Saturn Astra at the attack at the university. Firstly, she doesn't break the physical steering lock, and secondly, this is impossible to hotwire. It requires a signal from a chip in the ignition key that transmits the signal to the ECU to enable the car to start.
Factual error: In the opening of the Shanghai scene, there's a helicopter in the scene of the transformers fight. The helicopter has words on it meaning "police" in Chinese. But Shanghai use "Gong An," not the "Jing Tsa" seen here. Both of them mean police, but different words are used in China than in other Asia countries.
Factual error: The Autobots/N.E.S.T. base is said to be on Diego Garcia, a real military base in the Indian Ocean. The island in the movie is not D.G. The movie version appears to have hills and sparse vegetation, the real island's a tropical climate, and the highest point is about 22ft above sea level.