Continuity mistake: Jimmy buys three bowling balls in the second-hand shop and walks out with them in a small carry bag. He tosses three balls over the fence at Howard's car, but then later he is shown in his kitchen with Kim destroying one bowling ball in the same little satchel.
Continuity mistake: The scene with the fake address was shot on two different days. The sky is cloudy and it appears to be raining or snowing earlier in the sequence. By the end, it's sunny.
Continuity mistake: Jimmy gets ambushed. One gang member holds a gun close to Jimmy's face, but in the next shot the guy is way further away from him and not even visible in the shot when Jimmy gets splattered with blood.
Continuity mistake: In the scene after Jimmy/Saul and Mike in the desert with the seven mil, they are each sitting on one of the duffel bags of money at the gas station. Mike puts his big drink up to his head and his watch reads 6:35 but in the next shot it reads 3:00.
Answer: It might be the Panavision cap he wore when directing his terrible commercials.