Could your csas have gotten kicked off momentarially? I find nose =-20 degrees is normal flight in a BK in turbulance. Seems you are always fighting to keep the nose on the horizon even in light turbulance. Of course I could have had the problem and not known. It's also possible the gust was too much for the csas to handle. It's not a very good system compared to the single pilot IFR SPZ 700.
Give me the S-76 any day.