I did some quick tests and see something similar (I’m on 10.1.400 , and do not have Adv Mtl Mngmnt).
Not having AMM, My only choices for Dispose to are: Job, Fail and Stock

- The RMA Receipt was done for Qty 1. This created the RMA-INS parttran
- Processed the RMA with 0.5 going to stock, and the other 0.5 failed.
- The return to stock made an INS-STK parttran.
- The Failed, made a INS-REJ
- None of those PartTrans (RMA-INS, INS-STK, or INS-REJ) sho on the WIP/Recon
- This might be because mine test had a part with zero cost. And zero cost transactions don’t create GL transactions. And the WIP/Recon uses the GL Posting engine.