Well, after watching the video about 1000 times... I have decided that the right roll was only experienced when a forward cyclic input was made to oppose the pitching up. When it first vibrated it only pitched up. No roll at all. it makes sense that if the disc only stalls at the 90 point, you would only feel nose up, and past 90 the relative blade airspeed begins to climb. Forward cyclic would increase that blade angle and aggravate the stalled condition and force a longer stall in terms of blade rotational position. Add your 90 degree phase lag and guess what, right roll. But I have been wrong before. Lol