Lowheightbug, I think the helicopter you describe probably had an anti clockwise (when viewed from above) rotor so the powerful retreating blade vortices are on the port side of the aircraft. If you now blow these vortices by introducing a wind from the 10 o'clock or by hover taxiing left and forward, the vortices get shed into the tail rotor, thus reducing it's efficiency and therefore requiring more left pedal to produce the correct anti torque thrust.