Have you looked at that result recently? Ancestry.com recently reanalyzed the DNA results. The hispanic heritage that was in my DNA "disappeared" with the new analysis, while germanic heritage showed up. This actually makes some sense; my name came from a German who immigrated back in the 1600s.
The limitations of the DNA tests lie in the fact that they rely on statistical analysis. The larger the reference base is, the more accurate the DNA test.
I heard about that. My ancestry is mostly Polish, some Lithuanian. With all the times Poland was partitioned by the Germans since the Middle Ages it’s probable there’s some Germanic heritage in my family as well.