Testing against core.qa.collectionspace.org using Safari Version 12.1.1 (14607.2.6.1.1), this is what I did and encountered:
In Action 3 of Test 3, on the record Foo Three A, I added back the broader context Foo Two
I saved the record.
Upon attempting to delete, I received a message about both broader and narrower contexts (not just narrower contexts): "Foo Three A cannot be deleted because it belongs to a hierarchy. To delete this record, first remove its broader and narrower records."
In Action 4, I removed the broader and narrower contexts.
I successfully saved the record Foo Three A.
I (apparently) successfully deleted the record and (but?) was brought to a search results page titled "Local Places containing "Foo Three A:" There was one result: Foo Three B.
I opened Foo Three B and, using the Adjacent Places (i.e., equivalent context) link in the Hierarchy section, navigated back to Foo Three A. Clearly, the record had not been deleted!
I attempted to delete the record Foo Three A at this point, but received the following error message:
"Error deleting Foo Three A: Request failed with status code 400: Update request failed: workfloworg.nuxeo.ecm.core.api.ClientException: Unable to follow workflow transition: delete"
Foo Three A is no longer listed on the record for the common broader context, Foo Two, so there is no way to remove it from its equivalent-context relationship with Foo Three B.
Testing against core.qa.collectionspace.org using Safari Version 12.1.1 (14607.2.6.1.1)