The excommunications were not simultaneous. The Roman Catholic papal legate was the first to excommunicate Patriarch Michael Cerularius. And it was done by placing the letter of excommunication on the altar of the Hagia Sophia during a Mass. Only later did the Greek Patriarch issue his own excommunication.
Was it right for the Catholic legate to excommunicate someone purely because of political disagreements?
There are many missing details to that excommunication and what led up to it. It begins with the delegate who was NOT fluent in Greek, his personality and vendetta against all who attack the Chair of Peter and the Catholic faith. Plus the pope had already been dead before the excommunication was placed.
In summary, the facts proved neither excommunication were enforced by the whole Church.
Although, what remained from this action by the pope’s delegate; the Orthodox disposition of making the false claims that the West fell into heresy and or reject the filioque mainly on their own misunderstanding’s of the filioque, not to mention the authority of Peter’s Chair, in addition the reasons some of the Orthodox Church’s rejecting communion with the Bishop’s of Rome, when the Bishop’s of Rome do not reject communion with the Orthodox who remain in schism with chair of Peter.
The question today is not the excommunication taken place in1054. The problem and the question is worse than any excommunication when it is a lack of communion. This lack of communion should be the subject of discussion, and needs to be addressed by each autocephalous Church independently with the bishop of Rome, or a council. **The past unofficial excommunication no longer serves a purpose that infects the schism today. **
Was it right for the delegate to place an excommunication? Was it right for the Patriarch of Constantinople to call the Pope a heretic without first communicating his personal objections and dealing peacefully about such church disciplines and theological expressions with the Pope? Was it right for the Eastern Patriarch to compete for the Chair of Peter when it is never his to rule from? The excommunication did not stand and nor did the Patriarch’s false heretical opinions of the Pope stand.
Reasons for the schism is not the excommunication, the unofficial schism began long before, when the Emperor placed a Patriarch in his new Rome Constantinople.
Pre-Constantinople, all Patriarch’s and Apostolic see’s remained in full communion with the bishop’s of Rome Peter’s Chair.