Pass coverage lapses is the difference between 2-2 and 4-0

That says everything we need to know about the defense. That scenario is common in the NFL. The offense scored 3 touchdowns today and won TOP by nearly 9 minutes. The defense needed to hold up for 60 seconds and had no plan to do so.

The offense and STs also spotted the Clowns 14 points.
The offense mismanaged the clock on the last drive.
Koo kicked a 58 yard FG on 4th and 10 to win the game.
Atlanta only gained 30 yards on that last drive.

And the defense did what it's been doing since the season began.