It might be quite the opposite! The study itself concludes that “for individuals with mixed exposures to asbestos, all exposures should be considered”.

Yes, but the study still shows that people with no environmental exposure still got cancer. It's still explicitly stating that talc exposure is asbestos exposure. If J&J's argument is that these researchers made their product look more dangerous than it is by including people with environmental asbestos exposure in their studies -- whether by accident, or for nefarious purposes -- and therefore creating a false link between talc and cancer, this paper side-steps that issue entirely by including people with and without known exposure, and showing that talc exposure is equivalent to environmental exposure.

If J&J is saying what I think they are saying, then the researchers made these products look more harmful than they were, and included people who would have been harmed by other exposure to asbestos but concealed that fact in the study.

Proving that they concealed this information would be difficult, I think, though it would be devastating not only to their bank accounts, but to their careers more generally. Emory, Maddox, and Kradin's study explicitly states:

One hundred forty subjects with documented exposures to cosmetic talc were initially reviewed. Exposures were identified through sworn deposition testimonies and answers to sworn interrogatories provided from subjects, parents, and spouses. Sixty-five subjects were excluded due to recalled occupational or paraoccupational exposures to other sources of asbestos.

So, that wouldn't even be a lie of omission. It would be straight academic malpractice. Their academic careers would be over.