Rhys is pretty sure it would be death to end up on his back so when he loses his balance from her shove he rolls to the side faster than she can pin him. The ravens mob her on that side, shrieking and stabbing with their beaks as he regains his composure, bringing his spear up to slash at her. It's not as efficient a cutting weapon as it is a stabbing weapon, but he just needs to break skin and see if the poison works.