It could be a good sign that he is aware he does not measure up, rather than hypocritically pretend.
None of us do measure up against a perfect standard or perfect God.
He would just love coming to know about IMPUTED righteousness, where anyone can be granted a right standing with God as a "free gift" that cannot be earned, deserved or paid for.
What if you were to ask him to mark every occurrence of the words righteous, righteousness, justification and justify in Paul's letters? Possibly you could then ask him to explain how righteousness is attained according to Paul.
In time you could ask him to explain "law vs grace" and "faith vs works" according to Paul.
That just could be his ticket out of the apostate Watchtower organisation.