In her first appearance in the series, River questions the Tenth Doctor about the crash of the Byzantium, an adventure she shared with the Eleventh Doctor. While this makes sense if she is mistaking the Tenth Doctor for a Twelfth or later incarnation, her photo collection in this story has all of the prior Doctors in chronological order. This, coupled with her insistence that the photos are the only incarnations of the Doctor, implies that she does know the correct order, and therefore would also know that the Tenth Doctor would have no memory of the Byzantium.
If River had already dug up the wreckage of the spaceship 400 years later, why is she surprised when she recognizes what planet it is crashing on?