@Victoria1263 I find it pretty odd that you are posting this, when you don't seem to have been a part of this booking. Can your friends who made the booking not write a post themselves? And you have no way of knowing whether they caused damage or not if you weren't there. Just because they're your friends doesn't mean they are incapable of causing damage. People can damage things without even being aware that they have, it doesn't necessarily have to be purposeful.
I had a guest who called me up to her room 5 minutes after checking in to point out that the shelf in the closet was loose (I had noticed it while cleaning, but forgot to screw it back in properly). Because she didn't want to be blamed for it. That's what smart guests do.
The fact they wrote a great review isn't in any way material. It was obviously a nice place if they left a great review. Reviews aren't about "You write me a great review and I'll write you one." They are meant to be honest, whatever that encompasses.
Perhaps the host is making it up, but none of us have any way of knowing. Reading past reviews the host has left of previous guests is usually a good clue. If the host has a pattern of leaving bad reviews and criticizing their guests, then I'd doubt the host. If they don't, and your friends are new to Airbnb and have no reviews, I'd believe the host. If your friends had reviews and they were good, it would be hard to know who to believe.