He thinks he's in the right because he's a narcissist. He only thinks about himself. He'll admit that it wasn't the smartest thing to do but deep down, it is all about him and his situation was just that special enough to warrant driving under the influence. Not the fact that he puts potentially dozens of innocents in danger from his fuckwittery, no, it is all about Amir0x. Same goes for his break ins and mother beatings. He probably knows it is wrong but he is just that special of a snowflake that it is all justified for him, regardless of what others think and feel about it.
I think he is full of shit about the 13 drinks. If he had them in a short period of time, he would have passed out, even if he was a fat fuck. He could be (and probably is) lying about a number of things.