When Atticus and Heck Tate are having an argument do they believe what each other are saying?

Atticus and Tate are arguing about how Bob Ewell died. Atticus is convinced the Jem stabbed Ewell as he tried to protect Scout from attack. At the same time, Heck knows that Bob did not die because of Jem, but Boo Radley. He also knows that if Boo Radley were trialed for murder he would be discriminated against and would be a traumatic and painful experience. So, Tate tells Atticus that Bob Ewell had fallen on his knife while in a drunk stupor. Though Atticus does not agree, Scout is convinced that Tate is correct, telling Atticus that sending Boo Radley to trial would be "sort of like shootin' a mocking-bird.