Plastic Ejection Pin Marks On Older OGP Capsules?

I just bought a 1984 Olympic 3-coin set off ebay. The pics for the transaction were outstanding and everything went well. When I received the item, I examined the $10 gold eagle with a 16X loupe and noticed a perfect circle or ring marking just above the designer's initials. It was obviously on the plastic capsule since its shadow was evident on the coin itself underneath and changed in shape with different lighting angles. I looked for the same thing on the 2 silver coins- BOTH had circles of the same type and size, the '83 was at about 10:00 position and the '84 was just above the "S" in TRUST.

Some posts in here have pointed to the idea of plastic injection pin marks on slabs, etc... could this be found on mint packaging also?

Is this a "known" thing with OGP holders at that time, or really at any time? Or is this a more "modern" issue that should raise a BIG red flag? This is a $700 item at stake here and I have never seen anything like it before... any ideas?