It happened to me, luckily not often,
to have guests that kept saying that everything was good, either fantastic, during their stay, and then they come out with bad reviews after the stay.
I don't know if that happened to you but it is extremely frustrating and should be not accepted by Airbnb rules.
My guess is that they don't come out with request during their stay because they don't want bad reviews from the host.
I had a guest who kept saying everything was good,and then gave me 3 stars complaining that the shower was not working well, which turned to be true, but I don't have a crystal ball to gaze into, if I knew I would have fixed, as I did in no time after his departure.
I had another guest, even worse then the previous, that same, kept saying everything was absolutely amazing and then he left a very detailed review explaining everything that was not going well during his stay.
What made it worse is that he complained about lack of services that it was clearly written in the description that are not in the apartment ( like washing machine or wifi).
Did that happened to you as well?
Don't you agree with me that this behaviour is absolutely petty and despicable?
Airbnb policy should allow to remove reviews of guests where there is a clear proof that they declared that everything was fine during their stay and then unfairly hitted the hosts.