Legal Alien: A Scotsman in Montreal

Just how much do you trust your local scientist?

Looking at the potential catastrophes that could wipe out the human race and this one caught my eye:

"we did some calculations to find out if the Brookhaven particle accelerator was capable of forming such a black hole. We are now pretty certain this state of matter won't form at Brookhaven and that the Earth won't be swallowed when these particles collide"

So exactly what does "pretty certain" mean? Wouldn't that suck, the human race gets so far and then suck ourselves into oblivion.