The Gemara (Sotah 11a) states that before Paroh decided what to do with Am Yisrael he asked three respectable people what to do. The three he asked were Bilam, Iyov, and Yitro. Bilam was the one who came up with the idea of throwing the baby boys into the river, Iyov was silent and did not give Paroh and ideas, and Yitro fled to Midyan. The Gemara goes on to say that Bilam was killed by a sword, Iyov condemned to terrible suffering, and Yitro was merited to having his descendants sit on the great Sanhedrin in Jerusalem.
The Brisker Rav asks that if we know that Hashem always rewards and punishes according to our deeds, then we understand why Bilam was killed in the way he was. Since he proposed murder, he himself was put to death in the end. But how do the punishment of Iyov and the reward of Yitro reflect what they have done.
Iyov was punished with extreme illness. Sick people moan, groan, and complain a lot about their illness or sickness. The sick person knows that his screaming or complaining does not help him get better in any way, but he still does it. While it is true that Iyov could not have stopped Paroh from enslaving and harming the Jews, he could have showed that the decision Paroh made was wrong and that he was troubled by the hearing it. Because Iyov kept silent when his words could have meant something he was punished by having terrible pains and when he cried out, his cries accomplished nothing at all.
As for Yitro, he was chosen as one of Paroh’s top three advisers and he chose to flee the land. If he would have stayed in Egypt and agreed with Paroh’s plan he and his family would have been subject to a life of honor and riches. Yitro did not choose to stay and instead he ran to Midyan. Because of his choice to give up the honor he would have gotten from Paroh he was “Zocheh” to have his descendants sit on the Sanhedrin of Jerusalem, one of the greatest honors possible.