The Case of the Laughing Lady - S9-E1
Continuity mistake: Professor Toby is shown in the background as someone in the audience is highlighted, but is supposed to be on the witness stand and appears there in the next instant.
Perry Mason (1957)
1 mistake in The Case of the Laughing Lady
Starring: Raymond Burr, Barbara Hale, Ray Collins, William Hopper
Hamilton Burger: Incompetent, irrelevant, and immaterial.