1983 Planchet Error After Strike?

I suspect that this is post-strike damage, possibly a combination of chemical and mechanical damage. I don't like the way that the Memorial looks flattened in those areas where it hasn't been entirely erased. I don't like how the right lower steps are pitted. Some areas do look like a struck-through error, like where the N and E of ONE are abruptly interrupted. However, these can't compensate for the many signs of damage.

It looks like a corrosion issue rather than struck thru grease. The coin looks like it was exposed to some kind of corrosive substance or had been laid down on it's reverse on the ground. It looks like it's been cleaned and reverse shows several zinc rot spots that has been popped.