Yes, I agree this observation does closely resemble Idaea sp.(1), see Moths of Vic Pt 3 'Teasel Moth' as reared by Wendy Moore (=WendyEM) on dried Teasel plant material at Coburg in 2007; or indeed be idaea inquinata 'Rusty Wave', an apparently recently introduced species to Australia from Europe. See on iNaturalist ;- https://www.inaturalist.org/observations?subview=map&taxon_id=466365 This observation, if able to be confirmed, by further observation or collecting would establish the species also occurs outside of Victoria in southeastern NSW.