Unpublished documents not to prejudice public

If a document required to be made available in accordance with section 7, of this Act, being a document containing a rule, guideline or practice relating to a function of a Ministry or prescribed authority, was not made available and included in a statement in the Gazette, as referred to in that section, a member of the public who was not aware of that rule, guideline or practice shall not be subjected to any prejudice by reason only of the application of that rule, guideline or practice in relation to the thing done or omitted to be done by him if he could lawfully have avoided that prejudice had he been aware of that rule, guideline or practice.