First of all, physics does not "prove things 100%", so the answer to your topic is no.
Actually there has been some legitimate research done in this area, and there is some tension between FRW models and observations, see for example http://arxiv.org/abs/arXiv:0805.1132
. I do agree with you that the sentence is ridiculous, but on a scale of wrongness, it could be more wrong :-)
and BAO, and fitting all of them together.