This mint mark looks to match both 1982D-1MM-004 D/D TILTED (LDS) and 1982D-1DO-001 CLASS 2 + 6 (MDS) @CC. Is it possible that the MM is the DDO but because of the late die stage they don't realize it is the same die?
The location of the MM on the DDO isn't the same as the RPM. Could be a defect in the MM punch to why the vertical bar looks similar.
Is the planchet the 95% copper type or the Zinc core type? I would guess that the anomaly around the mintmark is either a plating issue or isolated mechanical doubling.
Here is an easy "DIY" way to tell if your 1982 cents are copper or zinc (second post on that page). http://www.lincolncentresource.net/forums/showthread.php?t=28306&page=3 And here is another (albeit blurry) "popsicle scale". http://lincolncentresource.com/smalldates/1982.html That being said, I'm pretty much positive that the coin you have is a copper-plated zinc, because there are no known 1982-D small date cents struck on 95% copper planchets. In addition, as Jay pointed out, the mintmark on your coin is not in the correct location in relation to the date for your coin to be 1DO-001. Mintmarks don't just magically move at random points in the life of the die. Taking the aforementioned information into consideration, I proffer that the anomaly seen on your coin is a result of the all too common plating issues found on the zinc cents of this period.