Westinghouse only closed Stone & Webster acquisition in late 2015, so it seems like the fraud started while Stone & Webster was still owned by CB&I.
The whole saga is bizarre because CB&I sued Westinghouse claiming it was paid too little for S&W [1] a few months after the sale was finalized, and then a few months later sued Westinghouse again [2] seeking to wipe out their liabilities in the S&W's businesses.