SKU Integration is enabled in BA. A credit/debit memo is created with the wizard, SKU is assigned. However the document detail does not have any SKU assigned. If memo detail is added manually (after memo creation), SKU is assigned properly.
An issue is caused by the bug with id #PBA-78172 ("SKU is not saved when creating credit/debit memo with wizard").
The bug is expected to be fixed in 7.0.2.