Nonpublic "executions" are merely exit strategy.
I can just imagine all the kvetching now.
"Irans nuclear program was a threat ti isreeeeeeeeeeal!"
"Yeah , so we killed the scientest running it."
"But we wanted waaarrrrrrrr!!"
Unless you're going all north korea and using an anti-aircraft gun "death by firing squad" could be a 9mm to the back of the head under the stairs. Any executions not carried out in full view of the public are suspect.
You'd think the media would have learned by now to at least tell plausible lies.