User blog comment:CenturyKiller/Earth Like Planet Found & Any News on ME2 or 3?/@comment-217683-20100930233552/@comment-217683-20101001002523

It's important to note that no scientist (at least not in the article linked above) actually stated that they were 100% certain scientifically or that it was the consensus of the discoverers that there was life on the planet. It was one scientist saying that he himself believes that there's a 100% chance of life being there. The article didn't include the full quote, but it's:

"I'm not a biologist, nor do I want to play one on TV. Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say that, my own personal feeling is that the chances of life on this planet are 100%. I have almost no doubt about it."

So it's just one man making an educated guess, nothing more.