Normal For A 1980-D LMC?

Looks like either a small die chip or a small hit, I'm more confident in the former

It looks like a hit to me as well.

No, there's no extra thickness on the date. Just a well placed hit. PSD.

The big DDO is on the 1980 Philly coin:

Note how the DDO makes the size of the devices irregular? They are enlarged, but not equally. On your coin the '0' is distorted, but check out the direction. Towards the closest rim. So what you are seeing there is die wear. On the 'IN' on the other side where the contact mark is seen, towards the rim, it appears as MD as it is flat on that area. Part of the inside of the 'O' is also showing that same Machine Doubling. How do I know that it is Machine Doubling? Look again at the inside curve on the right side of the '0'. Note the minor lines on that area? Those are called striation lines. Why are the important? The show where the metal was pushed with the side of the die. These striations lines appear often on machine doubled areas.







If you want to see how these lines are created by sideways movement, if you have a warm stick of butter in a tray. Take a paring knife and hold the blade vertical. Then lightly slide it across the butter. You will see these striation lines. Because of the metal movement. So when you see this on an area you question as being a doubled die, remember it is part of Machine Doubling. (Even happens on doubled dies) A doubled die has the doubling on the die, not created by the strike of the machine. So just like Machine Doubling often affects normal dies, it does the same thing on doubled dies as well. Hope this helps.
CoopHome : Striation lines