nor able to sweep up brick dust on the floor for decades because it is “destined” to be reverse-bullet damage that is fixed in the future.
(In the movie, you see them walk into a pre-damaged room that is later ‘repaired’ by the inverted gunfire that caused it)
Is not a “plot hole” if you simply accept that we cannot comprehend reverse entropy.
For example you could “plug” that “hole” with the assumption that free will doesn’t exist and all of existence is predetermined. There were bullet holes in the wall from the perspective of those going forward, because there had to be in order for entropy to work for those going backward.
The movie is fun because it makes you think — assuming you find thinking fun. Actually it’s also fun if you just turn your brain off and watch things blow up.