Thats one way of looking at it.
The other way is if the defense didn’t play that well the Falcons wouldn’t have needed a game winning FG with 2 seconds left. They would have blown the saints out.
The secondary plays hard and fast for 4 quarters, and they were banged up, of course they’re tired and make mental mistakes late. If you don’t want the game in their hands then do better for the other 58 minutes.