You have zero idea who rated you what beyond what you witnessed. It is possible a pax from a previous week finally got around to rate you for example. No way of knowing. Don't let Uber contro you this way by obsessive worry over what is nothing but bullshit. Do your thing. It's only about control and distracting you from what really matters. Focus on your expenses, the number of drivers in your market, making the job easier....... pay less attention to noise, this being a prime example.