While this phrase has become somewhat cliche, this is a perfect example of a case where it is important to remember the principle. Considering the types of disease that these medicines are meant to treat, I think it's pretty obvious that some, if not all, of the "side effects" mentioned could just be symptoms of the underlying disease, which were apparently not effectively treated by the medicine. But this is quite different from saying that the medicines themselves actually caused the symptoms.

Of course the article could end up being totally right. It was just poorly argued in my opinion because it failed to address this point that any reasonable reader would consider.