I thought it was asbestos that caused the disease?

Ahhh, mesothelioma. I wasn't paying attention. Years ago, when I actually had to learn some of this in epidemiology coursework, it was a causation given: "If you find a case of mesothelioma, you have found a case of asbestos exposure" . Studies could identify no other cause.

That may well still be the case, tho' a quick Google turns up some interested parties talking about synergistic effects -- in essence that smoking increases the likelihood of mesothelioma in asbestos-exposed populations/individuals.

Farking asbestos, farking tobacco.