Free will & the grandpa paradoxon

If you're interested in science fiction, quantum physics &c, then you've certainly come across the brain wracking grandfather paradoxon arising out of the concept of time travel: A time traveller could go back in time and kill his own grandfather, thereby preventing his own subsequent conception.

Here is a quantum mechanical, thus somewhat technical paper (via NZZ) that introduces an interesting solution to this paradoxon which also impinges on the free will vs. determinism debate. For the philosophical bits, cut right through the equations to section V (p. 10): (...) it is perfectly logical to assume that one has many choices and that one is free to take any one of them. Until
a choice is taken, the future is not determined. However, once a choice is taken, and it leads to a particular future, it was inevitable. It could not have been otherwise. The boundary conditions that the future events happen as they already have, guarantees that they must have been prepared for in the past. So, looking backwards, the world is deterministic. However, looking forwards, the future is probabilistic. Good!