I have faced an issue , when I was working with a client i.e the user have rejected the material with out inspecting the material. Also he is not the responsible person to inspect the material. By mistake he have done the UD for that material. Then he raised a ticket to do the UD reversal. Also here we are using inspection type 03 - Inprocess inspection.
On Implementing this code in user exit QEVA0008 we can reverse the Usage decision status from UD to UDREV