I have to disagree. These engines don't have that much torque to cause that violent a roll. P-Factor however is very strong and will cause a severe yaw to the left, which in turn will cause an uncoordinated stall and violent roll to the left. On the go-around the pilot was low speed high AOA high RPM. This caused severe yaw to the left and some rolling most likely. The pilot most likely attempted to counter with ailerons, which most likely contributed to the imminent stall spin. When the power was reduced the airspeed had probably increased and P-factor goes away, ailerons are now effective and not countering the yaw so it rolls rt quickly to 90 degs rt. Pilot recovers and most likely adds the power slower or with some nose down and avoids the same mistake. The corrective action to this mistake is to add opposite rudder and reduce power until and drop the nose until control is regained, then come back on power a little more smoothly using rudder to counter P-factor. Manks 7477 does this at all sound like what may have happened?