Jimmy's facial hair differs from shot to shot when Ash confronts him in the safe house garage towards the end. The make-up application in the mids and close-ups is completely different to the rest of the movie.
When Ash walks out of Jason's apartment for the first time, she leaves her phone on the couch. However, she is using it in the very next scene.
Jason's phone is first seen to be an old, damaged iPhone 4. However, when Ash calls Jimmy for the first time, she (presumably) pulls out Jason's phone and it's now an iPhone 6.
When Ash confronts Julian at the gym, one of the goons can be seen wearing glasses in one of the tight shots, but not in any of the other shots.
When Ash walks into Jason's apartment, in the wide shot a masking tape cross marker is visible in front of the fish tank.
Whenever Walter uses the phone in his office, nothing is displayed on the screen, revealing that the phone is not being used.
In the wide shot of Jimmy and Ash in the car right after the tavern shootout, a crew member is visible behind Ash, to the right of her headrest.
The furry boom mic can be seen behind Ash throughout the car scene following the farmhouse shootout.
During the second extended shot of the final shootout, as Ash and Jimmy approach Walter's office, a person holding a camera can be seen at the left of frame, emerging from a window.