It should be pretty obvious if you look at the bearing. It'll be all scraped up. Here's a link to someone else's pic: http://fireandfuel.com/spun bearing.jpg
There was a decent article in Hot Rod Magazine back in 2003 or 2004, it had pictures of several different bearing conditions with descriptions of each. If I had closer access to the mag I'd dig up the article. Maybe this will get somebody else's gears turning...
Mine looked like there was a thin covering that was flaking off in spots. The color underneath will be different than the silver parts that haven't flaked off.