I tend to be of the opinion that unnamed sources are fine so long as you identify them as such. People should take an unnamed source with the grain of salt. Some times there's a good reason why someone would be an unnamed source, but sometimes its just because they're afraid of being identified because they're perhaps not being 100% truthful about their own role in something.
But when a host says he is pulling from "multiple published sources," and then can't back up what he says with the exception of 1 source that isn't what he said it was. That's simply slinging mud.