I think the Oz nods were more to make an allusion to Oz throughout the episode. The whole thing was Regina trying to get back the thing she loves, making her a stand-in Dorothy. And she goes along with the ‘scarecrow’ (The man who lost his mind: Jefferson), the ‘cowardly lion’ (The man who lacked courage: Rumpel) and the ‘tinman’ (The man in search of a heart, Victor) but there was no wizard to be found, as much as she willed it, and instead the events released the evil that she “had inside her all along”. So it was a misdirect, it was a possible foreshadowing for future uses of Oz, but it was also an episode-sized allusion to a favourite classic.