The hand translation in this cast causes the instantaneous center (I.C.) to remain below Mathias's hip for much of the cast. It is not until a point around the maximum angular velocity of the rod that the I.C. moves to a point near his elbow, and then it moves behind him as the rod rotation is slowed down and stopped.
With no rotation the I.C. varies wildly at the end of the cast.
Many Thanks to Grunde Lovoll for sharing his high speed (500 fps) video data, and the extensive analysis he has done on the dynamics of flycasting.