there are two correct answers there if you dont look at the big picture. in nil wind the induced flow is the same value across the disc. as you introduce airflow over the dics the induced flow is decreased at the front of the disc relative to the airflow more than the rear due to the action of the blades but never the less the induced flow is reduced over the entire disc.
transverse flow effect is a product of this imbalance causing the machine to roll slightly right in a conventional helicopter. as the disc wants to flap back due to aerodynamic influence at the front of the disc the reaction is 90 degrees later in the plane of rotation causing the inflow roll.