Is This A Barber Dime Error?

This is a 1912 Philadelphia Barber dime however there is something not right as you can see. But I would like confirmation. The "M" in America is gone but every other letter is in fantastic condition. It is physically impossible for that one letter to be that worn down without signs of that much wear on the other letters or the coin itself. There is no trace of grinding, etc. I'm thinking mint error? But would like others opinions please. I would grade this coin VF20 with all letters of liberty showing.