As you can clearly see from the pictures below, there is significant blood transfer onto the duvet. This proves that Meredith was covered before the blood dried. This wasn't a staged crime scene. Evidence shows that Meredith's body was covered shortly after she died. Rudy Guede covered Meredith's body with the duvet.
a website detailing the wrongful conviction of Amanda Knox & Raffaele Sollecito
Pictures of the Duvet taken from the police video