I guess so, yeah. One situation where proverse yaw comes into play is on an aircraft (such as the MU-2 that our wonderful Boris flies) that uses spoilers for roll control. For example, if you want to roll left in the MU-2, the left spoiler pops up, reducing lift on the left wing. It also increases drag on the left wing, creating yaw in the direction of the turn, or proverse yaw.