Continuity mistake: When Jimmy is talking outside the courthouse, pretending to be his secretary, he puts his case on his car roof. In the first shot the white aerial is visible in front of his case. Shortly afterwards it's hidden, either behind or on top of his case, without him touching anything.
Continuity mistake: After James hits the roller blade guy, when the two brothers run away the sun changes between shots.
Continuity mistake: While James is arguing with Tuco in the desert about the twins the sun changes in several shots.
Continuity mistake: In the desert when Tuco and Nacho are interrogating Saul, the sun and sky change half a dozen times. When he is being cut free, the sun is to his left. The next shot it's overhead. The continuity gradually improves as the scene goes on.
Continuity mistake: Out in the desert when Jimmy is tied up, they decide to let him loose. Tuco's thug goes behind him, and James has his hands duct taped behind is back. The thug bends down to cut the tap, and then the camera cuts to a rear view. As the thug pulls the tape away, Jimmy's hands are suddenly instantly in front of him at his sides and he's leaning forward.
Continuity mistake: When James McGill returns from the toilet, Craig Kettleman is rubbing his hands. In the next shot he is holding a cup with the right hand and his left hand is hidden under his right arm. (00:25:05)
Continuity mistake: In the parking garage, the guy to Mike's right starts talking about the blood of some ethnics running hotter. When he says it's physiology, Mike is looking straight ahead. The camera then cuts to a wide angle showing all 3 guys and now Mike is looking off to his left.
Continuity mistake: While talking to Marco, when the bartender asks them if they want something else, James McGill is holding a beer bottle in his right hand. In the next shot the bottle is in the center of the table. (00:20:00)
Continuity mistake: During Jimmy's rant during Bingo, B5 is flashing on the main board (the last number he read out loud). It switches to B2 flashing when he says he got on top of the BMW. B5 is then seen flashing again, on the board in the back, when he's finishing his rant.
Answer: It might be the Panavision cap he wore when directing his terrible commercials.