The Texas Supreme Court's 2007 opinion in Flores established that those exposed to asbestos needed more than just the usual regular, frequent, proximate exposure evidence. Flores requires some evidence pointing to the actual amount of fibers given off by a product and what level a plaintiff might have been exposed at. The opinion was generally considered a down day for plaintiff asbestos litigation in Texas.
On the heels of that is Judge Mark Davidson's February ruling in Whetsell. In that case, Judge Davidson denied a motion by Garlock Sealing Technologies that would have striken Dr. Victor Roggli's opinion that mesothelioma can be caused by exposures of .01 fibers per cubic centimeter. You read that right, .01 fibers/cc.
Causation in Texas requires a showing that the risk of a disease is doubled. Judge Davidson thought that the Roggli had met this standard.
Judge Davidson doesn't shy away from difficult rulings and is famous for "baseball" ruling, his "mother of all" hearings on chrysotile and his reference to the federal asbestos MDL as a "black hole."
Nor is Judge Davidson shy about appeals, and he will occasionally encourage a party to appeal a decision for clarification from above. I would suspect that this ruling was almost certain to garner an appeal if the case hadn't settled shortly after the ruling. Sources told me that they expect this issue to come up again. Not surprising since Judge Davidson said "the smount of time I would like to give you-all to go into it would be a repetiition of our original chrysotile ruling. I really wouldn't mind this being another one of those."