I'd be surprised if he had said he'd prefer the F/A-18 over the Tiffy. His remarks may be politically incorrect (since he is RAAF and his country chose the SHornet), but they are not surprising. The Tiffy is better one on one. Now, in a real war where it would (in most cases) not be one on one, and where the possible adversary would be China or Indonesia, then the RAAF SHornet does quite alright since it would be backed by other SHornets, AEWC, Aussie navy ships/anti-air missiles and quite possibly even USN Aegis destroyers and/or USN SHornets. Thus, it is more than good enough against the current threat.
However, the Tiffy is still the better plane. Easily.