Not that I necessarily agree with what she's saying, her comment isn't on where "the study goes wrong", but rather about the fact of the study itself.

In the same way that, for instance, an evil genius can be said to have created a "good" bomb, the "good" here refers to its efficiency, the number of people it can kill, the speed at which it can be activated etc. but these qualities speak nothing of whether the bomb is a good thing - for that question you need to consult the context in which it was made, and the question is of course different and mostly irrelevant to the technical parameters of the bomb. The ethics of killing have nothing to do with how long the blade of your knife is.