I understand nothing much would have happened BEFORE the TOB was pressed, but afterwards i would expect the new PF command to take priority and the aircraft to take corrective action according to the new command??
Correct. That's exactly what would have happened and it's nothing much. Aeroplane takes corrective action but it's very remote from the snap roll. It takes a while for controls to move to their commanded position, aeroplane inertia dampens response even more, roll rate is limited to 15°/sec ang G to +2.5/-1 gear up, +2/0 gear down.