It’s fairly common for a writer to accidentally leave out the word not and thereby write the opposite of what they intended.
But I feel like it’s less common for other kinds of typos to result in a reversal of meaning.
I just came across one:
It was an intense feeling of fatherless.
Based on context, I think that was meant to say something like fatherliness; the sentence before and the sentence after make clear that the feeling being described has to do with feeling loved and approved-of by a particular fatherly person. But dropping the in from the middle of the word turns it into its opposite.
(I came across this in Nina Kiriki Hoffman’s 2003 story “Flotsam,” as reprinted in The Year’s Best Fantasy & Horror: Seventeenth Annual Collection.)
I welcome other examples.