It has nothing to do with his OT actions or behavior. Its about his PT development. By E2, he's already arrogant and feeling he's better than his masters, with nothing to justify the belief other than "I think this about myself". Desperate to be crowned, actually comparing any of his skills to Yoda's, and constantly trying to rewrite the Jedi code to suit his corrupted worldview, PT Anakin could only move toward greed, arrogance and eventually evil.
In the wake of his mass murder of Sandpeople (yes, even the children who were innocent of the situation with his mother), instead of feeling even an ounce of guilt, he screams that they were animals, then follows that with more self-aggrandizing fantasies about what kind of power he will gain over all. This is not some reaction exclusive to his mother--it is clear he had always believed he should have more power, that he was someone above the rest (not meaning the Chosen One idea) and rarely--if ever--listened to anyone. This was PT Anakin--the same fool who thought (based on no investigations / evidence of his own) that Palpatine suddenly talking about things he should not know--was correct...more than the Jedi. Why? Because Anakin was always right, and everyone else is either "holding him back," hiding things from him (again, based on what investigation / evidence?), and any thought ending with Anakin gets what he desires, and anyone standing in his way suffers. It goes on and on.
The patterns of evil were rather obviously laid out in the PT without anyone thinking about ./ referring to OT Vader.
He pushed his own buttons, because like Jinn, he would always "do what he must" no matter the consequences.
