For someone who calls Tokyo his childhood home, I do think that the picture you posted is highly offensive, distasteful, and crosses the line. A pic of Fukushima to make fun of the bid is fine, but the h-bomb actually killed thousands of people. It's the same as posting nazi pics to make fun of the Munich bid or crop sharers to make fun of the Chicago bid.
Being overly politically correct is unpleasant, but there's a time when joking stops being in good humor.