How Is An Error Not An Error .

The term " Mint Error " , which is used to describe irregularities on a coin that may have the potential to increase that coins value, is not an exact description of a time cutoff for the event that caused the irregularity.
The moment that the dies start coming away (and that means the precise instant of direction change) from the surface of the coin after their final strike of that coin , is the cutoff point for irregularities to be considered valued mint errors.

Metal being pushed out of position, gouges, impressions from other coins... ect , could yes , happen to a coin from all the moving about that happens in the mint after the coin is struck, but , this same type of irregularity can occur outside the mint. Because of this , these types of damage are not considered valued mint errors . Thus , the need for the cutoff point I described above.

What you see on the coin in your previous post is the metal that composed the vertical portion of the L of Liberty has been pushed out of position. Your own photos do prove this. The lighting position in one photo shows both the angled bar in question and the vertical bar of the L . In the other photo, the lighting angle was changed and only the angled bar is prominently seen. This difference actually proves that metal has been displaced from the vertical bar of the L .
This could only have happened after the dies left the coins surface. This means that it doesn't matter if this alteration to the coin happened before it could exit the mint or after, it is not considered a valued "Mint Error "

Here Kanga
http://goccf.com/t/354638

I would agree.

@ziggy, I don't want to pile on, but would like to add one small thing. For sure coins can and do get damaged while they are still on the mint premises. However, this "mint damage" is indistinguishable from PMD as a practical matter. Perhaps consider only coins for which the specific issue can only have occured at the bank.

I'm glad that you are pushing back a little to better understand what you are seeing and I look forward to additional threads from you.

Here is a photo from your earlier post. The arrow is pointing to where the L was originally. If you look closely you can see a "shadow" of it remains in the original position. The upright was moved after the coin was minted