You are, of course, terribly wrong and rather uninformed, P-Marlowe. The papal legate (of a dead Pope!), with no commission of authority, took it upon himself to excommunicate the Patriarch of Constantinople in 1054!
But this did not cause the Church of the East to break relationship with the Church in the West in "protest." What a distortion that would be!
For centuries, at one time or another, the names of various Bishops were not read at Divine Liturgy, and no one really paid much attention if the names in the triptychs -- of the bishops with whom a particular Church was in communion -- were up to date or not.
The Orthodox and the Catholics did not create a man-made church as Luther did. They simply stopped communicating in the Eucharist because it became obvious that they no longer shared the same faith. Lets be brutally honest: the Latins changed the theology without a General Council of the Church in agreement. Instead, they often followed the local Councils and treated them as Ecumenical Councils in authority.
They didn't see it as something sinister; they developed a different mindset over the centuries of linguistic and liturgical separation, influenced by different political realities, and subjected to different linguistic concepts and cultural influences. They simply grew apart, split (which is what schism is), and stopped talking to each other at one point -- a couple of hundred years after that fateful excommunication in Constantinople!
And that was not the doing of the Orthodox Bishops, but of the lower Orthodox clergy and the people (laity). They, not the hierarchs, rejected the false re-union at Florence -- not in protest, but because the message from Florence was not what the Church taught for 1,200 years.
The Orthodox did not leave. They simply rejected the innovations. But that did not stop Patriarch Jeremiah II from admonishing the Protestants when Luther's followers contacted him in hopes of an alliance with the Orthodox against Rome some 30 years after Luther's death.
Patriarch Jeremiah II considered himself every way a Catholic, although not in communion with Rome. In fact, the Catholic name of the Orthodox Church did not become suppressed until after the Vatican I in 1870, when the real rift occurred between our Churches -- with the introduction of the papal infallibility dogma. And even then, the Orthodox did not "leave" the Church in protest.
The Church, whether Latin or Greek, remains Apostolic in authority, meaning that its bishops can trace an uninterrupted ministry and office to a particular Apostle. That gives both Churches valid clergy. Both Churches share the same sacraments.
Luther was a rebel. While his initial protest had merit, he continued beyond the mere "correction" of indulgences and other transgressions of the Roman hierarchy: he went on to redefine the Faith according to his own taste, intellect and liking. A big difference between the Protestants and the Orthodox.