Hi Merlin,
not being a melbourne person... I'm guessin it was for a ILS or VOR for 27?
in which case I'd say RMIT got it wrong..... kinda in the same way casa 'use to' get there answers wrong in exams....
as you said AIP ENR 1.5 3.2.1 point's to 230kts & the approaches aren;t limited to A&B cat and the only other possiblility would be for a note in the bottom right corner of the IAL but nothing there either (possibly may have been when question was written of course... lol)