According to this answer, you are allowed to market turkeys as fresh as long as they haven't been frozen below 26°F. What is the purpose of this law/regulation?
Water freezes at 32F, but turkey contains more than just water. Alton Brown answers this question in his original turkey episode of Good eats. The meat freezes at 26F, so they can call it "fresh" if it's kept at say, 30F (below the freezing temp for water).
The USDA recognizes "frozen" for a turkey as having been brought down to 0F. Apparently the middle range is called "refrigerated" (frozen, but not quite as rock hard as a bird at 0F).
Edit: The rules themselves make sense I think. At 30f your turkey meat isn't frozen. Now whether the transport and stores have it at 25f or 27f I don't know how strict they are. I could see turkeys crossing that 26f threshold because of human error.
Edit 2: As Ben pointed out. Surface ice is very likely as the bird itself is below the freezing point of water. Condensation will freeze on the surface as normal. It is the quality of the meat that is of concern.