Not an error - it was hit little by little with a spoon or hammer to make it look like that, maybe to make a ring. There are videos on Youtube that show guys making rings for your finger. There you can see the process. Usually made of silver quarters but yours is the same Post Mint Damage - I want to share this video with you -
A clothes dryer cannot cause the edge to be perfectly flattened all the way around from random hits in such a short period of time. I'd imagine it would be possible if it were in the dryer for many, many years, but you would also have heat damage to the obverse and reverse. Chris
