A value of TRUE for lpbDaclPresent does not mean that pDacl is not NULL. That is, lpbDaclPresent can be TRUE while pDacl is NULL, meaning that a NULL DACL is in effect. A NULL DACL implicitly allows all access to an object and is not the same as an empty DACL. An empty DACL permits no access to an object.
Attempting to run cacls on a shared folder in VMWare runs into this edge case.
According to MSDN:
Attempting to run cacls on a shared folder in VMWare runs into this edge case.