From their remarks, they understood exactly what was happening. I assume they were brass, which accounts for their enthusiasm. I wonder how they made out. I suppose if they didn't wait around for that cloud to settle on them, they might have been OK. I guess this is where "fully briefed" comes in. In the early tests, the hazards of radioactive fallout were not given the respect they required, to say the least, but by 1957, I would have thought they were more generally understood. Maybe it was a few more years before "fallout" became a bugaboo.
Fallout was not an issue here. Fallout comes from dust kicked up from the ground. An airblast well above the surface of the ground will have virtually no fallout. Just the material that comprised the missle and whatever dust that was already naturally floating in the air.
“I assume they were brass,”
Yup, there were references to “Colonel”, I think. You’d pick brass for a publicity stunt like this to be sure it went OK.
There would not be “much” fallout from a 1.7 kt airburst. The debris cloud would be hot as all get out but would not mass much. Serious fallout happens when the isothermal sphere (inner fireball) touches ground, then you get a kiloton of dirt irradiated strongly with neutrons rising up as a vapor, to rain down in little spherules that are very hot. Hiroshima and Nagasaki did not produce much either, and they were airbursts. Most radiation casualties there were from prompt effects.
The thermonuke shots that vaporized entire islands generated huge masses of fallout.
This shot was about the size of the Argus shot and neither would produce much stuff.