It's simple: GE is down, as of right now, over 11%. Knowing the sensational allegations of the report would have a short-term deleterious effect, they shorted the stock. They can turn the profit from the successful short around into buying GE at its depressed price, and profit a second time when the stock returns to normal levels after the report is found to be exaggerated.

This assumes the report is, in fact, exaggerated.