You mean like former disgruntled staffers making up stories about taping the Ram's walk through? That was gold. And suddenly it becomes a fact. The reality doesn't make as good of a story though (wiki):
The Boston Globe reported on March 10, 2008 that NFL investigators found practical limitations to the allegation; the Patriots' video equipment that was set up the day before the game had neither battery packs nor a nearby power supply in order to run.[8] Also, an NFL investigator interviewed a Patriots employee who left the Louisiana Superdome that day with Walsh; according to the employee, Walsh said of the walkthrough: "We should have taped that."[8]
Boston Herald writer John Tomase, who authored the story, told WROR-FM on February 5, 2008 that the "rumor had been around for a while. ...It was something we first heard about in September, after Spygate. We dug around and couldn't quite nail it down."