Spelling mistakes in published works are much more common that many people expect.
You only have to ask a professional proof reader to read over a sample chapter to stand a good chance of finding one or two.
How does this happen? On over-reliance on spell checkers is part of the problem.
For example, there are lost of words that sound the same but have different meaning (technically called Phonological ambiguity) so it’s easy to use the wrong word and have it go undetected. There are lots of them including: brake and break, bear and bare, sail and sale and the old favourites like there and their, too and two and even by, bye and buy.
If you’d like to take a look at common misspelling then take a look at