Aliovalent cation-doped fluorite oxide structures are ideal candidates to understand phase stability and their transformation pathways under radiation. These systems are relevant models for nuclear fuels and waste forms. Sc4Hf3O12 is a delta phase crystallising in a trigonal symmetry. This and other A4B3O12-type systems were observed to transform into a long-range defect fluorite phase upon low energy ion irradiations. On one instance Sc4Hf3O12 was also observed to partially turn into a bixbyite phase, however, the reasons behind this were never clearly understood. Thus, in the present study, swift heavy ion irradiated Sc4Hf3O12 was investigated as a function of fluence using x-ray diffraction. Structural parameters obtained from quantitative Rietveld analysis reveal that, while the long-range average structure develops into a defect fluorite, the local structure tends to convert into a bixbyite-like arrangement. Similarities in the polyhedra suggest this bixbyite-related local phase is a metastable system that effectively provides radiation resistance by creating large numbers of bixbyite-like replicas within an aristotype fluorite mesocrystal.