First of all, I don't think I came up with that term. I read in one fanfic or something. I may have turned it into a name, but I'm not sure.
Jimmy Interuptus is one of those phrases that crops up naturally out of chat. It was coined by...someone...during discussions, on irc, the mailing lists etc., of the episodes back when they were being first aired, and just caught on, so that soon everyone was using it. Whoever first used it is lost in the mists of time. I dare say over the years it's made its way into fanfic, too, so it's entirely possible you could have seen it there, Woody.
LabRat