Yes, despite the assistance Mr. Conroe has with editors and proofreaders, some mistakes will still make it through to the final version. However, the incidence has dropped off sharply in the last few years, so I try to focus more on the story than the “nuts and bolts” of the text. Although to save my sanity for subsequent readings I use Calibre to correct any errors I happen to find.
And to illustrate just how tough it can be to produce error-free writing, I noticed at least three typos in your relatively brief post. And I had to fix two mistakes in mine. 🙂