I'm sorry, but I'm skeptical. That whole 'correlation doesn't imply causation' thing. This is what - one person with one site? Out of how many total sites that were Pandalized? Sure, it'd be nice if this was the silver bullet (unless of course you depend on ads to monetize your site) but I am unconvinced. And my own observations and experiences are completely different (also statistically insignificant even with the number of sites I own and oversee)
(whoops, supercyberbob slipped in with correlation/causation while I was writing this, ork ork)
That said, the ad factor is definitely worth exploring, hopefully we see some more data from everyone else.
I would not be surprised if ad PLACEMENT were a factor, as well as the ratio of ad/nav/header/footer to content as well. But just having AdSense? I'm not buying it.