Normally no, you don't leave a copy if the signing is not completed; however, in the event of incorrect numbers as you cited, I would leave a copy of the CD for their reference when speaking to their LO (which, btw, what happened to the CD being delivered 3 days in advance? Isn't anyone paying attention to that rule any more???)
Misspelled names? I'd leave a copy of the face page of the DoT or Mortgage and the signature page of the note (signature space lined through) for their own proof that their names were spelled wrong. But take the rest with you.