1984 date means it's all Zinc with a thin coating of copper. A large fingerprint is across the face and it has those common plating bubbles. A true spender.
I don't understand why something that looks out of the ordinary, is considered an "error" first instead of first considered as "damaged".
Toning is not Damage but toning caused by the environment is. Environmental damage is caused by being exposed to the elements.
It really doesn't matter if it's damage or not. What I'm trying to say is that it is NOT a mint error.