When Vader’s shuttle exits the Star Destroyer in the beginning, it’s followed by two TIE fighters. The TIE fighters are far apartfrom each other, but in the next shot, they’re close together.
https://www.youtube.com/watch?v=qQB2NXfJev0&t=22s
When Vader arrives at the second DS and is talking to Moff Jerjerrod saying “Perhaps I can find new ways to motivate them.” during the last two words Jerejerrod’s mouth is moving as if he were talking, but nothing is heard.
https://www.youtube.com/watch?v=qQB2NXfJev0&t=2m11s
When the Gamorrean guards take Chewbacca to his cell, you can plainly see that when the guard closes the door you can only hear it close. You can still see that it’s open.
https://www.youtube.com/watch?v=TRh5wPCq1DA&t=2m55s
When Leia runs to the shield generator in this scene as the doors are closing she fires a shot from her blaster. It smokes, but there’s no blaster shot coming out of the weapon or sound effect when it’s fired.
https://www.youtube.com/watch?v=aHf1HY2FN5k&t=2m53s
In this scene when Leia is shot, the burn mark is already on her poncho before she’s even shot.
https://www.youtube.com/watch?v=VTa0qqLVIao&t=12s
From the inside of the rebel hangar it appears that the floor extends further into space than the roof as it goes past the walls on either side.
But from the outside, no such protrusion is visible.
In the Space battle when Lando says “Watch yourself, Wedge. Three from above.” then when Wedge says “Red 3, Red 2, pull in”, it is Green Leader who responds with “Got it”. Not someone from Red Group.
https://www.youtube.com/watch?v=xPZigWFyK2o&t=2m29s
When Lando says “Watch out! Squad at .06”, “Grey Leader” from the Y Wing squadron responds and destroys the TIE fighter. But Wedge (Red Leader) acknowledges this hit by saying “Good shot, Red 2”.
https://www.youtube.com/watch?v=xPZigWFyK2o&t=4m41s