What my colleague said is true: you expect that for some things, you're not going to get what you asked for.
One of the concerns is the gratuitous use of exemptions. Advice and recommendations are so broad you could drive a truck through them, and officials do, quite often. We've had solicitor-client privilege invoked for letters that are 100 years old. We've had third-party exemption invoked for materials that are 100 years old.
To me, that's a gratuitous use of exemptions, and the Information Commissioner's office has the expertise to address those issues. We certainly don't expect to get full disclosure all the time.