And it should be pretty easy to get a group of people with same level of asbestos exposure who haven’t used J&J’s talc and compare the cancer % between the groups. That’s where J&J should be focusing if they knew they were in the right.
Yes, that's how I'd do it.
Perhaps researchers did do this, and found that there was no difference, but decided not to publish that.
Who knows? But it sounds like J&J is confident that they can prove that researchers were hiding facts, or else that's an incredibly pointed accusation!