"I accept the bible is not inerrant..."
Of course, he didn't convert out of vacuum. I was talking to him two days before about why am I not an inerrantist. And after that, I forwarded a short article by Roger Olson to him. What happened thereafter is, of course (!), the working of the Holy Spirit in and on him.
It was not I who convert him since no one able to convert anyone without God's prompting. It is the Holy Spirit. Alleluia~ All glory to God~