Adapted From Messages From The Mishnah, Pages 13-14
The first opinion stated in the Mishnah is that of Rabbi Eliezer. Rabbi Abraham Twerski suggests that this was not an accident, but was done with intent in order to give honor to Rabbi Eliezer. Rabbi Yehudah HaNassi, who compiled the Mishnah, was a grandson of Rabban Gamliel. Rabbi Yehadah HaNassi, like everyone else knew what his grandfather did to Rabbi Eliezer.
Rabbi Eliezer and the Chachamim were discussing an impure oven that was dismantled. The unanimous ruling was that when it was dissembled the oven lost its impurity. However, when the oven was reassembled the Rabbis and Rabbi Eliezer disagreed about its status. The Rabbis said that the impurity returned and Rabbi Eliezer said that the pure status remains.
Rabbi Eliezer, somewhat famously, refused to yield to the majority and repeatedly tried to prove that he was right. First he asked a carob tree to uproot and replant itself- and it did. Then he asked for the river's support, and it flowed backward. Both times the Rabbis said that these supernatural acts were of no consequence. Finally he asked the heavens to declare that he was right. A voice from heaven announced, "Why do you dispute with Rabbi Eliezer? The halacha is always in accordance with him." Then Rabbi Yehoshua stated, "The Torah is not in heaven, it was given to you and majority rules." Rabbi Eliezer would not concede his position. Rabban Gamliel, the Nassi, felt he had no alternative and stepped forward and made the difficult choice of excommunicating Rabbi Eliezer.
Rabban Gamliel was once on a ship and it almost sunk in a terrible storm. Fearing that he was being punished for putting Rabbi Eliezer in cherem Rabban Gamliel cried out to heaven, "Master of the Universe, I did not do it for my honor or for the honor of my father's house. I did it so that there would not be an increase in fragmentation in Israel." And the storm stopped.
Rabbi Yehudah Hannasi knew not only what his grandfather did, he understood that he did it with a heavy heart. He had no doubt that his grandfather respected Rabban Gamliel greatly and therefore he started the Mishnah by honoring Rabbi Eliezer.