Sure. A lot of mathematics is out there; e.g., Shinichi Mochizuki's work on the abc conjecture is so far out other mathematicians can't evaluate it.

Think of fields or problems only a handful of people are working on. Usually because it is viewed as fruitless. Then somebody cracks it and sometimes a use is found for it. The rest is labeled "useless research".

So that's one example.

The test would be: not only was there no precedent or suggestion for it, but it turned out to be epochal.