Again, it is his job to corroborate before he reports. Otherwise, you get called out on it. Remember when Florio said Bradshaw was dead because a person reported it? He hasn't lived that one down and considers it one of his biggest mistakes. Obviously, that isn't on the same level, but it's relevant enough to support my point.
You don't see Schefter or Glazer shotgun blasting crap just to get it out there first. They try to get some supporting sources, that way, if they do end up wrong, they at least followed "best practices".