Well yes, but it's not always so obvious is it. Some typos, unlike 'teh' are real words.
If I type 'form' when I mean 'from' (a common mistake on my part when typing in a hurry using a traditional keyboard) it is a typo, not a misunderstanding on my part of what the two words mean or an inability to spell them.
I would hope that it would be obvious from the context that it was a typo and anyone reading what I had written would realise what I meant to say. They might judge my sloppiness, but they wouldn't judge my intelligence.
With other mistakes it is not so clear cut and there genuinely could be room for confusion. For example, if I was writing about the habits of a nineteenth century novelist, I might put 'everything was written in the dairy'. Someone reading that might wonder whether I meant 'diary' rather than 'dairy'? It might be obvious from the context but it might not. The reader may suspect a typo, but they are unlikely to conclude that I couldn't spell or that I mixed up the meaning of the two words.
Of course some people do have trouble spelling and some mix up words, but in general think that these days many common mistakes are more likely to be due to a reliance on predictive text and/or lack of proof-reading than they are to genuine misunderstanding. 'Definitely' and 'defiantly' probably come into this category.
Bought/brought, on the other hand, are more likely to be genuine mistakes, not least because they have been common errors for many years and because they occur regularly in spoken as well as in written English.