Sometimes people tend to throw around logical fallacies a bit too much. In the legal system it's perfectly acceptable to bring up such an ad hominem argument:

Sometimes people tend to throw around logical fallacies a bit too much. In the legal system it's perfectly acceptable to bring up such an ad hominem argument: motive. No one should be convicted on motive alone, however it does frame the interpretation of facts in a certain way. In this particular case we have a seemingly sensationalist article, along with some suspect data collection, and then a large jump from correlation -> causation about nuclear fallout. Once it is seen that the authors have a vested interest in damning nuclear power, it's much easier to draw conclusions about what's going on or to increase scrutiny considering the impartial nature of the researchers.