This will resolve true if e.g. a private organization / government / individual / etc. had made a discovery on the order of relativity / newton's laws / quantum, and kept it secret, until it's leaked / declassified / etc.
The size of the discovery must be world-changing (especially as measured in new capabilities), it can't just be some constant measured to a higher accuracy or whatever.
Let’s pin down what counts as a discovery. Out of these, what would count: the concept of nuclear fission? The fact that a specific isotope of some element undergoes nuclear fission? The synthesis of a new element? The cosmic microwave background? The discovery of cosmic rays? The realization that stars are powered by nuclear fusion? The discovery of neutrino flavors? The discovery of multiple stellar generations in globular clusters? A cheap chemical way to enrich uranium? The discovery of a new planet in the Solar system?