I bet somone’s face was red! This is the second-craziest copyright story I’ve heard, after the one about the monkey’s self-portrait. An image on Wikipedia from the 1964 Rudolph the Red-Nosed Reindeer TV film explains the following “permission details”:
“The copyright year in Roman numerals was mismarked as MCLXIV (1164) instead of the correct MCMLXIV (1964). This invalidates the copyright under U.S. law at the time, which required a valid date of copyright to be affixed to the production; this means that still images from the special and all of the characters unique to the special are, as a result, in the public domain. However, because the original story and song are still copyrighted and the soundtrack was validly copyrighted separately, for all practical purposes, permission is still required to air the special.”
It seems crazy to me that intellectual property could be invalidated by an obvious typo. No one actually thinks the film was created in the year 1164. (At the same time, it seems to me that use of the still, say, with an article is fair use.)