Reflection on event horizon for collapsing black holes
  It was argued recently that there exists an unexpected phenomenon, the reflection of incoming particles on the event horizon of black holes (Kuchiev(2003)). This means that a particle approaching the black hole can bounce back into the outside world due to those events that take part strictly on the horizon. Previously the effect was discussed in relation to eternal black holes. The present work shows that the effect exists for collapsing black holes as well. 
M.Yu.Kuchiev