Wow, thank you for picking up on that; it's a part of our canon that's very dear to my heart. I am sort of endlessly interested in why the Doctor ran away from Jack --I mean, nothing excuses the way he did it, but I like poking at the reasons, and that fixed point/fact statement seemed ripe for interpretation. And the Doctor changes things all the time, just by his nature. It also made Face of Boe/Jack's ability to "prophecy" work for me; he's seen it happen that way, so that's the way it has to happen.

Thank you so much!