Does load factor affect roll rate?
One of the best reasons to unload before using your ailerons is to make sure you are not 
stalled.  If you are, using ailerons could reverse and make you roll the opposite way.

Ailerons can be evil when used uncoordinated with rudder, yet very helpful rolling out of an inverted dive.  The danger increases if the aircraft is yawing and near stall.  So it is much safer to recover in 2 steps, unloading first.