misspelling (noun, plural: misspellings)
Simply means: a wrongly spelled word (or spelt! - contrary to what many think, this isn't a misspelling, but a seldom used form of spelled).
Typos, on the other hand, refer specifically to typographical errors (of which typo is an abbreviation), which appeared with the first printing press (see Gutenberg). They generally occur in printed material, or during the use of an implement or machinery whose output is print-like in appearance (including the printing press itself, typewriters, computers and their keyboards etc.).
An example of a misspelled word would be: phoenatically, used by the person who provided the previous "definition" of the word misspellings. Correct spelling of that word is: phonetically.
The reasons for assuming that he misspelled the word, and it isn't a typo, are threefold:
1) on the keyboard, the "e" key is not in the immediate vicinity of the two adjacent letters ("o" and "n").
2) the word phonetic has its origins in ancient Greek; many Greek words (and names) use the compound vowel "oe" (such as: phoenix, Phoenicians, or perhaps the best known one: Oedipus). Hence his confusion.
3) a practical reason: he did not correct his mistake, thinking it was correct.
So much then, for the differentiation between an ignorance-induced misspelling and a printing or typing mistake known as typo.
He picks on others for their misspellings, but ignores his own. He misspelled the word phonetically, thinking that it should be written similarly to phoenix. He was vicious towards those with mental and learning disabilities, because they had a medical explanation for their misspellings, unlike him.