The opening scene repeats the ending from Part 1, but shows Kaz and Tora already hiding behind a crate when Hux says 'All remaining systems will bow to the First Order' whereas in the part 1 they were heading for the door and turned around after Hux finished his sentence. His reaction to the destruction of Hosnian Prime is also different from part 1.
After Yeager and Doza stun two First Order troopers with their own weapons, the troopers are heard moaning as they hit the ground whereas they should already be out cold.