When Mannix shows Peggy the picture of his wartime buddies from Korea, he tells her the man he thinks is trying to kill him is on the left when actually you can see it's really on the right.
When Mannix is reviewing the film of the boxing match with Lt. Tobias, he asks the projectionist to sharpening the background of himself. It is impossible to do so once film is shot out of focus.
When Mannix is in the TV station parking lot he receives a threatening call on his car phone. He spots a man in a phone booth across the street who might have made the call. The man hangs up the phone at the same time the threatening call ends, comes to the station parking lot, asks Mannix for directions, then drives away. But Mannix never gets the car's license plate number to find out who the man is.