The system allows to fulfill a Vendor Return when on hand quantity = 0 and setting for Fulfill Based on Commitment preference is set to Limit to Committed.
User wants to disallow the Item Fulfillment of Vendor Return when on hand quantity = 0 same as the Sales Order.
There is an Enhancement Request logged for this feature request. See details below:
Enhancement #: 156725
Summary: Vendor Return Authorization should have an option to behave the same process as Sales Order in terms of committing the items and reducing the quantity available