I suggest three alternatives more plausible (to me at least) than that the NSA and its ilk outsourced something we know they like to do themselves. In increasing order of likeliness:
1. Israel supports them (obviously), so asked for a few countries to be left off the list unless they do an additional review.
2. When they were claiming not to do any business in the U.S. to avoid a lawsuit, they added it themselves to use as an argument.
3. They're lying and no such exception exists now or ever. These are criminals who aren't in court, so nothing prevents them from tossing out falsehoods.