But there was a public leak backed by none other than Jimmy Carter to show that he wasn’t soft on defense in the 1980 election. If Carter didn’t reveal the stealth’s existence to make political points it’s been theorized that it could have remained a secret until the late 80s, possibly into the 1st Gulf War. Remember this well but not much about it is on the web. Here’s some on it;
http://www.bibliotecapleyades.net/ciencia/secret_projects2/project317.htm
There were a lot of leaks in the 117 program, including intentional exposures of the airframe in places which were known to be photographed.
Shoot, even in 1986, in the brand new public lobby of an aerospace company, there was a nearly mural sized high quality photograph of the aircraft on the wall.
It was a different era, the intended consumer of the leaks was Russia, and they blew a tremendous amount of resources in deploying systems to counter this threat, far more than we spent building those planes.