(Athena): "To judge this matter is greater than any mortal thinks—and I certainly have no right to decide between pleas about shed blood where angers are sharp, especially since you, Orestes, have been submissive to custom and come in supplication to my temple purified and harmless; and I respect you as giving the city likewise no cause for blame—but these persons have an allotted role not easy to dismiss, and if they do not get an outcome which brings them victory, poison from their proud spirit will later fall to the ground and be the land's intolerable, everlasting sickness. This is how the matter stands: both courses, for you to stay, Orestes, and for me to send you away, bring harsh pain if there is to be no wrath against me. But since this matter has descended suddenly upon us here, [I shall appoint] judges for murder-cases, with respect for oaths under an ordinance which I shall lay down for all time, [a line missing] with no transgression of their oath through unjust minds." (470-484, 489)
At first glance, Athena's lines here seem weird. Even if it really is harder to pass judgment upon Orestes "than any mortal thinks," it is hard to see how she makes the jump from that idea to saying "I certainly have no right to decide between pleas about shed blood where angers are sharp." Why the heck not?
One possibility has to do with the specific context of these lines, with gods ranged on both sides of the issue. If Athena decides in favor of Orestes, she will anger the Furies; if she decides against him, she will anger Apollo. Could setting up the jury of the Athenians be a way of passing the buck, so that they will share the blame for any decision she does make?
On another note, it is interesting that Athena is especially pleased that Orestes has not defiled the temple, and thus has brought no pollution on the city. This doesn't really have anything to do with whether Orestes was right to kill his mother or not—it just gets him in Athena's good books from the start. This brings us back to the "you scratch my back, I scratch yours" idea of Greek religion. Does it raise any questions about the fairness of Orestes's trial?