I had the opportunity to learn a little bit about fingerprints during a programming gig. The part he's missing here is that what he thinks is a smudge can sometimes still be used as part of a print. Partials aren't just from TV dramas, they get used all of the time in real cases. Also one thing most people don't know about is that prints can be "massaged" by law enforcement in what is essentially a photoshop-like process, so if a human technician can make a fairly good guess about what the print should look like, they still might be able to find a match.