Precisely. To not discipline the congregant is to fail in your duty as clergy to call sinners to repent. If a man's soul is in peril, as Tiller's was, standing by idly simply compounds the sin. Our Lord confronted sinners directly and dutiful clergy MUST do the same.
I agree that pastors should ask sinners to repent. Have you heard any pastors preach a sermon against homosexuality, knowing that at least one gay person was listening? I haven’t heard of that.