The play was originally ruled an incomplete pass, then on review the refs reversed it and it went in the books as a fumble. However, since neither team made an active effort to recover the fumble, the ball reverted to Bears' possession at the spot where the ball came out of Cutler's hand.
So, although the Bears technically fumbled the ball twice that game, in the official stats the Bears are shown with only 1 turnover (since they retained possession on the other one).