I just listened to it over and over.
I do NOT believe he said “not”.
I heard, with a frog in his throat or a mis-forming of the words, “I’m a Christian”.
Listen again with THIS in mind NOT the salacious attempt to make it seem he said “I’m not a Christian”
“I’m a Christian”.
“I’m a Christian”.
“I’m a Christian”.
“I’m a Christian”.
He said I’M A CHRISTIAN
Sounded like “I’m a Christian” to me.