According to the report, they notified ATC they could not meet RVSM requirements once in cruise, but the requirements for RVSM (automatic altitude hold system) must be met before entering RVSM airspace. They had the problem before they entered RVSM.
You should go work at CASA with an attitude like that. They told centre they were non-RVSM, if it wasn't going to work Centre would have just said 'clearance not available descend now' etc etc. They may have also been RVSM compliant on the way up but not at the cruise. Noone knows and it really doesn't matter. They flew the aeroplane and that is all that matters. Only in Australia would someone be worried that you may or may not have broken the AIP for a couple of minutes.