Having read science fiction for most of my life, if put to the test I could probably remember more than 20 (mostly bad) stories about the effects of bombs and radiation.
Not to mention the entire Kaiju movie industry, the best known of which is GODZILLA!!!
Probably the guy really lucked out not only by being outside the actual bomb blast radii but also by not being downwind.
Studies of the effects of the most widely dispersed radiation, from Chernobyl, chart many radiation deaths, mostly due to Cancer, but not that much mutation.Chernobyl
So unless you were a Soviet/Ukrainian clean up worker, of a British sheep, or a Sami reindeer, or a Japanese monster, you're probably okay now.
mikezpen's comment was interesting. Nice to hear that someone could survive what we do to each other.