How would we know? Information (esp. sensitive ) was a lot easier to hide back then.

Also the iPhone leaked was an iterative-model not the original.

I think we know because an atomic bomb prototype would have been far too large and conspicuous for an individual to take to, let alone leave at, a bar :)

Not to mention the bar would’ve been in Los Alamos, a town run by the military.

Also there were rumors of the iPhone for yeeeeaaaars. I remember people jokingly referring to it as "the jesus phone" while speculating about it.