Lior: We have a Drashah (that utilizes a societal/sociological truth) that precludes women from being witnesses. No one today can change a Drashah. Maybe Bimos HaMashiach we will Darshan that Passuk differently or apply its sociological implications differently(or society will change back). I would expect that, when we once again have a Beis Din HaGadol, lots of things will respond to societal changes that have occured over the past 1500 years. But for now, an Ishah is Passul L’eidus.
But we don’t have any Halachic reasoning inherently precluding a woman from getting a Heter Hora’ah. That’s an important difference.