Reaching stick shaker obviously demonstrate that the AOA wasn't controlled in a way to enhance the glide performance. Since the AP was following the ILS the AOA didn't stop increasing, very far from best glide. Retracting flaps doesn't lead to AOA reduction (on the contrary if you wish to maintain a constant path), it only improve drag.
So S.F.L.Y., please tell us what you would have done so we can benefit from your superior knowledge!