He can correct me if I'm wrong but I'm pretty sure he is agreement with you that if a 'believer' is living in sin they are not saved to begin with. He has cited 1 John 3:6 before to make the point:
"6 No one who lives in him keeps on sinning. No one who continues to sin has either seen him or known him." - 1 John 3:6
Freegrace on the other hand, as you know, says the true believer can purposely continue in their old life of sin and still be very much saved. I don't think he believes that for a second. Neither do you, of course. You two are on common ground here.