The obvious answer to the question asked is yes. Whoever puts the e-book out to the market place, publishes it, is responsible for the quality of that e-book. This is no different than for a paper book, or any other product. Now as far as e-books go specifically there is no excuse for putting out a book with misspelling, grammatical errors, punctuation errors (unless any of these were the author's intent), nor with missing or misplaced passages of text. I can be a bit more forgiving of errors of formatting related to appearance given different e-book file types existing. Still it is still the case that whoever publishes the book is responsible for the quality of the product. Large publishing companies should do proofing of books that they put out as should authors that self publish.