Ok, I see the logic, but nuclear weapon use is the brightest red line in the world. If there's anything a government wouldn't be forgiven for, it's that. I can't imagine how the calculus for the US would work out in favor given the risk. (Of course that assumes rationality, which one could certainly argue is lacking, but even still.)
Also 1000ft is an upper estimate, right? It's certainly possible the MOPs were sufficient.