Should have of questioned him why he was drunk.
Then told him that JWS aren't solemnly righteous and wholesome people , there are pedophiles, alcoholics, wife beaters, child beaters. business crooks,. tax evaders, adulterers , fornicators.
Similar to what you would find within the general population.
Then you could have pointed out the WTS is a sinning apostate religious publishing house that God would never approve of.