It is well documented that the Nazis were farther from a functioning nuke than we believed. The Norwegian ski raid
Hero of the Telemark dies aged 101: WWII who carried out raid on Hydroelectric plant to thwart Hitler's nuclear ambitions | Daily Mail Online on their heavy water plant was not as successful as initially believed, but it was enough to prevent the Nazis from developing a nuclear bomb.
Proof that the Nazis weren't close to nukes is self evident. If Hitler had nukes, or had them within his grasp, he would have expenses all resources to develop them and would have used them. The fact that he didn't proves that he didn't have them.
The "Nazi nukes" headline belongs with a 75 year line of breathless headlines pronouncing various lost Nazi treasure that have never been found. The Amber Room is a more likely target than Nazi Nukes. And professionals have been searching for that since it was lost. Despite a hundred hot rumors proving where it is, the Amber Room remains elusive. Nazi nukes are even more elusive, since they never
Existed in the first place.