The poster is a Twitter-verified journalist for a major news site. I've issues with Salon's journalism at times, but it's at least a fairly reputable source.

Yes

No. It's a guy with an itchy tweet finger who wants to make headlines first and ask questions later.

Matthew Sheffield‏'s belief in the claim was not based on hard evidence at the time, but rather based entirely on two tweets from white supremacists known for trolling. He parroted the claim in the off-chance that it might be true. He's a gambler, not a reliable source.

Fair point and I agree that the tweet on it's own didn't sufficiently back up the claim. I posted the link in response to your comment for other readers who might stumble on this discussion.

In my case I did research the claim on my own and verified with other sources prior to submitting, as I certainly don't want to participate in spreading false information :)