Not many real journalists have even one source as reliable as Gruber's has been.

I can't imagine well-sourced rumors are all that commonplace about a company as secretive as Apple. Probably you have to go with what you're given on the rare occasions you get precious little anything at all.

I could live with that, if Gruber didn't make a point of serving up "claim chowder" every time someone else rushed to print a juicy tidbit without checking the facts. If you are going to throw stones...

I agree that in general Gruber has well-researched and thoughtful pieces. I would have more respect for his retraction if he didn't spend most of it telling me why it wasn't his fault.

"But, trust me, it was AT&T’s decision."

and then

"My source [...] was wrong."

You're implicitly giving a lot of credit to the stories he calls out as 'claim chowder'. They're pretty much always unsourced bs speculation from hacks and trolls who would never call attention to their own mistakes.

Is a leak like this something that a journalist could get a second source for?

Absolutely, that's why they get a second source. But you can run with a single leak as long as it's positioned as such and you give the other party a chance to respond. I don't recall how it was mentioned in the original article.