When deleting a file, all leases granting handle caching lease to the file should be recalled (as it is happening on Windows). In Samba this is not the case.
Searching MS-FSA for "18.104.22.168" (Algorithm to Check for an Oplock Break) it seems there's more missing, eg in
22.214.171.124 Server Requests Setting of Security Information
ie when a client sets a DACL we should check for H breaks.