I think that I remember reading an even better example about publishing scientific results that might have furthered the Nazis ability to produce a nuclear weapon in HPMOR, though I can’t recall where it was exactly.
Graphite as a neutron modulator, I believe. Ch. 85:
During World War II, there had been a project to sabotage the Nazi nuclear weapons program. Years earlier, Leo Szilard, the first person to realize the possibility of a fission chain reaction, had convinced Fermi not to publish the discovery that purified graphite was a cheap and effective neutron moderator. Fermi had wanted to publish, for the sake of the great international project of science, which was above nationalism. But Szilard had persuaded Rabi, and Fermi had abided by the majority vote of their tiny three-person conspiracy. And so, years later, the only neutron moderator the Nazis had known about was deuterium.
Graphite as a neutron modulator, I believe. Ch. 85: