When Sykes and George are chasing Harcourt and Kipling in the police car as they push them off the freeway they are on the driver's side, in the very next scene, they are on the passenger side of the car.
During the car chase when the criminals' car jumps the center curb while it's in the air the rear tire is seen and is twisted pointing 20 or 30 degrees towards the center of the car but after it lands they keep going and it is straight again. If it was damaged to where it was turned in like that the car would be unable to continue or would be swerving around and be very difficult to drive.
At the gun range, Sykes makes a speech to George about hunting down his partner's killer, then he turns and walks away. At this point James Caan forgets to take the gun. He then ad-libs, telling George to bring his gun.
When in their car, Sykes asks George for information on Hubley. At this point Patinkin opens a binder but instead of opening to the file, it opens to a closed folder, which is clearly in view of the camera. He then pauses, obviously thinking about faking it, then opens the folder and begins "reading" Hubley's information.
When George is hanging outside the helicopter, above the water surface, he should be screaming in pain since the rotor-blades would whip up a pretty dense cloud of seawater, thus he would be injured since his race is extremely sensitive against seawater, as pointed out by Joshua Strader, and William Harcourt in the end scene, their bodies react to it as we would to sulfuric acid, as referenced in the movie.
When Sykes is about to be struck by Hubley's son at the bar, Francisco stops him. The son then says something in the Newcomer language that is translated on screen as, "You smell like a human". However, he is only saying Francisco's real name, the same one Francisco himself told Sykes earlier, not a statement about him smelling like a human.