Not a Jujube

Apparently, that's so of qualified privileges and of the All Writs Act -- but what on earth does that mean?

From Judge Selya, in Havlik v. Johnson (1st Cir. 2007):

A qualified privilege is not a jujube that, like some magical charm, wards off liability for defamation, come what may. In Rhode Island, as elsewhere, such a privilege may be abrogated if the plaintiff proves that the privilege-holder published the offending statement out of spite, ill will, or malice.

And from the same judge in Trenkler v. U.S. (1st Cir. 2008):

Still, each attempted use of an extraordinary writ in connection with post-conviction relief must be judged on its own merits. The strictures of section 2255 cannot be sidestepped by the simple expedient of resorting to some more exotic writ. Put bluntly, the All Writs Act is not a jujube. At most, it constitutes "a residual source of authority to issue writs that are not otherwise covered by statute."

What does that mean? And how is it putting it "bluntly"? I know about the fruit and about the candy, but I just can't figure out how they fit here.