Rotated double or triple strikes do happen, sometimes the coin can even flip over and be struck again, but this one is misaligned and most likely happened like Mike said. It pays to be educated on coins if you're going to shop
ebay.
Here is a genuine rotated double-strike in collar from Jon Sullivan.

There are more images of some of these on this page:
http://www.lincolncentsonline.com/error3.htmlIf someone had a genuine example of this, it would be worth the time and expense to have it certified. Beware of raw errors if you are not familiar with them.