When Hal and Carol are dancing in the bar, they start with Hal's right arm extended, a reverse of typical leading position. Midway through their dance, he's leading with his left arm extended without their having switched.
In the final scene with Carol Ferris, Hal is shown wearing his mask, and in fact, Carol asks him to take it off. Yet Tomar-Re specifically told Hal that his mask would appear when his identity needed to be hidden. Since Carol had already figured out he was The Green Lantern, there would be no need to hide his identify.
While being chased by Parallax, Hal flies from the Earth to the Sun via the Asteroid Belt; which lies between Mars and Jupiter, in completely the opposite direction from the Sun. It's also a common error to portray the Asteroid Belt as being crowded, when it's in fact largely empty and hitting an asteroid is something that would require careful aiming as the asteroids are spread over such an enormous volume of space.
In the test pilot scene, it is claimed that the F-35's service ceiling is 50,000 feet. Its real service ceiling is 60,000 feet. And exceeding the service ceiling doesn't cause an aircraft's engines to flame out like in the movie. But none of this matters, since if they were testing the air superiority capabilities of the drones, they should have been testing them against an air superiority fighter like the F-22, not a multi-role strike fighter like the F-35.
When Hal materializes the necklace for Carol's late birthday present, it's gone a couple of shots later. This is because items are only around as he is willing them. They are not permanent and go away when he stops thinking about them. This has always been his way in the comics and cartoons, and also explains what happened to all the other objects he conjured throughout this film.
Hal destroys Parallax on the principle that the bigger you are, the faster you burn up. While this applies to stars which must generate heat to resist gravitational compression, the opposite applies to objects heated by the sun - since the smaller you are, the less mass you have in relation to your surface area.
During their climactic battle, Hal and Parallax rise vertically from the ground into space where a handy satellite is floating nearby - but since it's in a low Earth orbit and they aren't, the satellite should flash past them at the great speed of five miles per second.