I'm not sure I can tell. Why? From the screen shot it doesn't look like it has finished scanning your drive yet.

Ah. There didn't seem to be any indication that it was still scanning. I assumed that it was done and was screwed up. There wasn't even any real disk activity. Is there something on that screen that indicates that the scan isn't complete?

(The one thing that I don't like about Scanner is that it basically blocks until it's done scanning, with no apparent way to cancel, but it does give a progress indicator, and you at least know when it's done.)