This should hold up, I've already checked out the paper... the science is there, unless they are flat out lying about their experimental data. I would like to emphasize that this is not a "direct detection" of gravitational waves. This is detecting an artifact of (primordial) gravitational waves, which is almost as good, but should only serve to justify LISA and future generations of gravitational wave detectors. As the article states, this does absolutely confirm inflation, and is a major victory of cosmology. Also, this doesn't necessarily confirm or nix the multiverse theory, that's something still shelved in the category of "unknowables", at least with today's technology and physics. It's an exciting time to be alive, but we're not done. :)