It's funny, but I'm 100% sure that John Carpenter saw the original airing with this prologue added, and created the next year the screenplay for what was to become ESCAPE FROM NEW YORK, starring Kurt Russel, with the very same basic premise (ie convict felon is given pardon if he accomplishes his mission).
Everyone knows Carpenter is a western addict, and that all his movies are westerns in modern settings. Makes sense.
It does. This had never occurred to me before, but what you say sounds plausible. Good thinking and welcome to the board.