Trivia: Robert Forster filmed his scene in this episode at the same time that he filmed his scene in El Camino. He is having a phone conversation with Bob Odenkirk, but Odenkirk shot his part later. Unfortunately, Forster passed months earlier (coincidentally on El Camino's release date) and sadly never got to see his work in neither this nor El Camino.
Trivia: The scene in which Saul tricks a witness on the stand into identifying a defendant that he had swapped out with a doppelganger may be based on a real-life incident from 1994, in which a lawyer swapped out his client with a lookalike, leading to the arresting officer for the case to misidentify the defendant. The judge presiding over the case then ordered a not guilty verdict and held the defense lawyer in contempt for deception. He ended up only having to pay a $400 fine as punishment.
Answer: It might be the Panavision cap he wore when directing his terrible commercials.