Ummm, as someone who has tried to take black and white pictures of aerial fireworks in the bright sunlight (as Ric would say, I don't wanna' talk about it), I can safely say that something like an aerial flare would not show up as a black dot on the actual print. It might show up as a black dot on the negative, but on the actual print, it would be white or light-colored. And even given that there is a contrasting background, it still looks like just a glitch on the 70-odd year-old print. To me at least. I leave more definitive diagnosis to Jeff Glickman.
Also, FWIW, aerial flares, on bright, sunny days, don't show up all that well. It's a little better on cloudy days, as it was in this photo, but not really that much. Flares are for nighttime survivor-finding. During the day you want either smoke or a mirror, which produces a much brighter flash.
LTM, who takes care with who he flashes,
Monty Fowler, TIGHAR No. 2189 CER