I doubt they have backdoors into our SQL Server instances

Based on the information made public so far, the documented behavior of the NSA in particular and governments (of all stripes) in general, I think your attitude has little to recommend it. On the contrary, it is instead highly likely that they did not overlook SQL Server (or Oracle, or any other db platform) as an important source of information that needed to be accessed. It is highly likely that they indeed do have backdoors into our databases.