If you are looking for certainty in science, you are looking in a wrong place. Science has been and will always be probabilistic and never certain. If you want certainty, try religion or ideology.
What baffles me the most is how spin doctors (I am not talking about you, but in general) turn the probabilistic nature of science into jack-ass, smart-alec certainty that there no connection at all. It works more or less like that: Scientist: "The evidence at hand shows that X may be linked to Y" Smart-alec jackass: "Are you sure?" Scientist: "There is about 60% probability." Smart-alec jackass: "But not 100%?" Scientist: "Of course not, but...." Smart-alec jackass to the audience: "Just as I told you. Those eggheads think so but are not sure. So the only thing we know for sure is that there is no proven connection between X and Y."
Wojtek