Revealing mistake: During the fight with Fallon, Kimble's stunt double is glaringly obvious. He's taller and thinner, and doesn't even have the same color hair. (00:43:50)
Revealing mistake: When Kimble leaps from the truck and runs into the woods, the stunt double's face is visible. (00:07:00)
Revealing mistake: At the beginning, the stunt man seen running toward the train in profile (when Kimble jumps aboard the freight car) is very easy to spot. (00:01:50)
Revealing mistake: Matt Mooney pulls open the freight car's door, and we can see the swiftly passing landscape outside, but not a hair on his head is disturbed by the wind. Rear screen projections don't generate much of a breeze. (00:10:05)
Answer: Production vehicle models aren't in sync with the calendar year. The '65 Mustang began production in March 1964 and first sold in April 1964, before it was "introduced" the following year. I don't know which model was seen in the episode, but the 2+2 fastback was sold in September 1964. The 1964 film "Goldfinger" uses a 1965 Mustang as part of Ford's product placement. Basically, in the 1930's, FDR ordered automakers to release vehicles in the fall of the preceding calendar year "as a means of facilitating regularization of employment in the industry." Now, automakers can release new models as early as Jan 2 of the preceding year.
Bishop73