Gaffes

In the first shot scene, the train was moving in one direction when the first shot was taken, but when the video is shown on the phone, the train is moving in the opposite way (the trees through the window), which could not happen, as it was a high speed train and it couldn't just stop and reverse.

When Henry and Danny go out to dinner at the waterfront restaurant, in the wide shot the sun is shining brightly and the dock post behind Henry is in full sunlight. When it cuts to his close-up, it is completely in the shade. When it goes back to the wide shot, it is again in bright sunlight, all within a span of a few seconds.

Since Will Smith played both characters they have an identical accent. This is a common error in fiction with clones -the clones of Jango Fett all speaking with his accent, for example. Since accent is not a genetic factor but is influenced throughout a person's life and develops based on environmental factors it is impossible for these two characters to share an accent so perfectly. The same is true for personality, likes/dislikes and moral imperatives.

Near the end of the film Henry shoots a Standard Manufacturing DP-12 shotgun while holding it in a completely incorrect way. The DP-12 is shown in the film to fire two 12 gauge shells (in this case seemingly incendiary rounds) at a time. Anyone who has fired a 12 gauge shotgun knows the heavy recoil involved. If you double the force by firing two rounds at the same time, there is no way this weapon would not have flown out of Henry's hands.

Clones with a surrogate are less identical than identical twins because of the additional genetic data the surrogate has to impart. It would not be the copy that the movie suggests.

Correction: The surrogate imparts no genetic material. The surrogate is simply a living incubator for the cloned fetus.

When asked about 3 buildings on the Darien campus of UGA, the answer is McWhorter Hall and Rooker Hall. These are on the Athens campus of UGA. Rhodes Hall is also in Athens at the Health Sciences Campus, though separate from the UGA main campus.

Someone who has a severe bee allergy would never inject epinephrine into their arm, the delay in the medication getting into the blood could kill Henry.

Epinephrine via intramuscular is the preferred route for a severe allergic reaction. This is why they prescribe epi pens for anaphylaxis situations that are meant to inject in the muscle.

During the shooting scene in the liquor store, there was no spilled liquor on the floor; only glass.

No highly trained, cold-blooded assassin looking for a hidden wire (radio transmitter) would tell a woman to "Take your clothes off" and then let her keep her bra and panties on, the obvious place to hide a wire. Also, a group that can clone, have high tech armor etc, can't use a scanning device or jamming device against a wire? Seems so unprofessional.

When Henry and Danny pick up junior from college near the end of the film all closely surrounding students remain standing unnaturally static. This setting is extremely unbelievable.

At the end of the motorcycle chase, Junior puts his bike on its back wheel and lets it crash into the car Henry is leaning against. It hits the car violently and flings over the hood. Windows smash, but the door and side panels remain totally undamaged.

When Brogan checks the map for his Budapest appointment with Yuri, the name of "Nagysezo Street" is briefly shown. This is a typo as the actual name of the street is "Nagymezo".

So that he wouldn't question their strong facial resemblance, Junior was never shown a photo of Henry, but it's unbelievable that a highly trained assassin would try to hunt and kill a target that he couldn't recognize on sight, or not even question why this information was being kept from him, since this ignorance would greatly increase the chance of him killing the wrong person.