Reply with truth. That's the bottom line. For Christians taught to wear the armor of God, the sword of truth is our weapon. NOT using your weapon is agreeing with the enemy. "Nothing to see here."
Very important that the nightwatchman respond to the enemy coming. Ezekiel. If he doesn't sound the alarm he is responsible for what happens to those he did not warn. If he does sound the alarm then the people are responsible for their own decision to take up the sword (of truth), or not and suffer the consequence.