The key part in the show - or one of them - for this question is the interview for the first time with the KGB agents who were working at the Embassy in Mexico City and who said they met and talked to Oswald over two days. These were very serious men in a very serious occupation who were astonished at Oswald's behavior. Oswald was, according to them, acting erratic and unstable and at one point brings out a revolver and waves it around saying he needed it for protection from the "notorious FBI." Remarkable.
They all said that the man they met over two days, the man who behaved like this was, was Lee Oswald. It is simply inconceivable to me that an impostor trying to pull an impersonation off would act like this.
Is this proof? Could they have been wrong? Yes. But if we look at the other evidence - the other eyewitnesses, the physical evidence, the circumstantial - it all points to Lee Oswald being the man they met.
They weren’t “wrong.” They simply lied.
They met with the so-called “unidentified mystery man,” who was one of their KGB colleagues in the CIA.
The KGB officer impersonating Oswald spoke with a KGB officer named Kostikov, who “specialized in handling Soviet agents operating under deep cover in the United States,” which, of course, included KGB officers inside the CIA.
Kostikov was “believed to work for Department Thirteen of the First Chief Directorate of the KGB. It is the Department responsible for executive action, including sabotage and assassination.”
I have first-hand knowledge that Warren Commission Exhibit 237, the Mexico City “unidentified mystery man,” is a photograph of one of President Kennedy’s three assassins.
It’s all explained in my book.
https://www.amazon.com/dp/B07V9JT65Y