@Shelley369 The review is not that negative, at worst, a host would think they needed to give more detailed instructions on how to leave the property, I can't imagine that this comes anywhere close to defamation of character. Your responses indicate you've stayed at other Airbnbs, but this looks like your only review, that seems odd. There is absolutely nothing in the review that suggests any kind of discrimination, so you might want to let that go.
Yes, it's a good idea for guests to take video when they leave an Airbnb to protect themselves, just as many hosts take video before a guest arrives for the same reason.
ETA..I'd offer an alternate theory that this host is new and may have unrealistic expectations on cleanliness, and/or their previous few guests were smaller parties w/out children. If they think that 4 hours is 'extra' time to clean up their property, then they probably have been very lucky in their guests. It takes us 4 hours to clean our 2 bedroom apartment, which we might possibly be able to clean it in 2 hours working as fast as humanly possible, but only if it wasn't really dirty.