Late-time correlators in semiclassical particle-black hole scattering
  We analyse the quantum corrected geometry and radiation in the scattering of extremal black holes by low-energy neutral matter. We point out the fact that the correlators of local observables inside the horizon are the same as those of the vacuum. Outside the horizon the correlators at late times are much bigger than those of the (thermal) case obtained neglecting the backreaction. This suggests that the corrected Hawking radiation could be compatible with unitarity. 
A. Fabbri, D.J. Navarro, J. Navarro-Salas and G.J. Olmo