I'd like to offer an alternate, fourth option: we know that this general region of the coin is often struck up weakly due to the majority of the metal flowing into the die to make Abe's bust. Perhaps this blank was a little bit light on metal and just didn't strike up as much as the mint would have liked.
"If you climb a good tree, you get a push."
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz