It's all damage. The Copper plating was compromised and the inner zinc rotted. Just Environmental Damage.. Corrosion. Not a Mint Error
Get used to this, people - I predict all unprotected zincolns will look like this in a few decades - planned obsolescence by the Mint
A few weeks ago, I was walking through the parking lot to my favorite Publix grocery store when I spotted a half cent on the ground. I picked it up only to discover that it was half of a Crappy Zincoln. Chris
Looks like a BB gun holed coin. I used to do that when I was a kid to see it it would go through and how high into the air I could shoot the coin from the end of the barrel.
Metal Detectors of the future will find no "stinky zincs" in the ground because they corrode to nothing quite quickly.