I had to reread the module explanation a couple of times before it clicked for me. Here's a potential explanation.

Admin marks "Notes" field in the Fields UI for the Story content type as "Edit own field" and "View own Field". User1 creates Story content type and adds text to the "Notes" field. User1 saves the Story node and see's their the text they entered into the "Notes" field. User1 clicks on edit tab for the same Story node and modifies the text in the "Notes" field. User2 has permission to view and edit this node (granted by another module). User2 views the Story node that User1 was just created but does not see the "Notes" field. User2 edits the Story node that User1 just created and does not see the "Notes" field on the edit form. User2 does not see the Notes field because of the "Edit own field" and "View own Field" settings on the "Notes" field. Only owners of Story nodes can see the "Notes" field with those settings applied.