As @muddy pointed out long ago you’re not reviewing the guest, but the guest’s conduct (and that of his group) on this occasion. If you look at the standards of review per Airbnb this guest will still likely still get 3 or 4 stars on cleanliness.
It’s important that the words of the review reinforce what the guest did well, so we’re not just pointing to the ‘spot in the rug’ for an otherwise good guest (though I don’t think you caught this guest at his best, what with something broken, no heads up about that or the bed, and super-short messages (“Thank you”) that left you guessing on what was intended to being communicated.
Neither do we, but others here might want to chime in here on whether they wash the mattress pad [not the mattress encasement] with each turnover. I believe that I’ve read that many do, but I’m not sure of that, and am wondering if doing so is a best practice.