I would say post-mint damage, rather than a possible mint error. It's likely something heavy was placed on top of it, squeezing the lines into one side and squeezing flat the details on the other side. Perhaps the coin was sitting underneath a large piece of furniture, or even used in the foundation of a building.
In my 2002 edition of the 1600s catalogue, KM# 12.1 has a value of $6.50 in Good, while KM# 12.2 has a value of $7. Though if I saw your coin in a dealer's shop window here in Australia, it would probably have a $40 to $50 pricetag on it.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis