It’s not the fact that they experimented with air-to-air atomic weapons. I understand the basic thought process behind that. It’s not even that they had people standing right underneath it when it went off. I assume that the basic danger was low, although you probably should never assume that when it comes to the intrepid pioneers of the Atomic Age.
It’s how dang chipper they are about the whole thing.
Personally, I’d be a bit worried about how much fallout is going to get generated from a pure air explosion (you’d still get at least a little) and where it was eventually going to drift down. But then: I’m not an intrepid pioneer of the Atomic Age. Those guys probably had to jockey to get a spot at Ground Zero.