In line 69 Antony says he is not there to "disprove'' what Brutus said. Is this or is this not true?

This is absolutely untrue..... Antony will turn the people and disprove Brutus merely in the way that he speaks. His flattery is flattery..... but it is also sarcastic. He successfully manipulates the crowd by repeating himself..... by drawing the eyes of the crowd to the man who was slaughtered like an animal..... worse than an animal.