The potential optative with ἄν is used to soften the statement of an opinion or fact, or to express irony: ἕτερόν τι τοῦτ' ἂν εἴη
a. With a negative, the potential optative may have the force of a strong assertion:
οὐ γὰρ ἂν ἀπέλθοιμ', ἀλλὰ κόψω τὴν θύρα_ν
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].