Mr Awe wrote:
Alidar Jarok wrote:
Unless you're wrong, in which case you've just altered a fixed point in time.
It's just like replacing the Doctor with a lookalike robot. In this case, you're planting a headstone to keep up appearances.
The Doctor didn't replace himself with a lookalike robot. The Tessalect always was shot, he was just mistaken about it being the Doctor.
It's been shown that the Doctor has some sense of what a fixed point is. He figured out that not dying didn't destroy the timeline there, but he's also figured out that replacing Rory and Amy but leaving a tombstone would alter the timeline.