Unlike all other Australium weapons, which have an envmap applied to only the gold areas of the texture, the Medi Gun has it applied to the entire surface area of the weapon.
(comparison between Australium Scattergun and Australium Medi Gun, note how the Scattergun's non-gold areas are completely matte while the Medi Gun's non-gold areas still have a gold sheen to them)
This is due to the Australium Medi Gun mistakenly not having blacked out non-gold areas in the texture's alpha, unlike all other Australium weapons.
Unlike all other Australium weapons, which have an envmap applied to only the gold areas of the texture, the Medi Gun has it applied to the entire surface area of the weapon.
(comparison between Australium Scattergun and Australium Medi Gun, note how the Scattergun's non-gold areas are completely matte while the Medi Gun's non-gold areas still have a gold sheen to them)
This is due to the Australium Medi Gun mistakenly not having blacked out non-gold areas in the texture's alpha, unlike all other Australium weapons.