There was a recent study that showed what he said was legit. Sean claimed that study was debunked. All that shows is that scientists can be wrong.
Just as an aside... you used the word "legit", short for legitimate, which was another part of this debacle. Even if it has a meaning of "legally established or accepted" it has a common usage meaning of being "OK" or "on the up and up". And this wordplay will form the basis of relentless soundbiting of this killer word use. In the case of the medical study you cite... it has never proven to be "legit", as in used in court or a legally precedent setting basis.