More about Parting of the Ways

[owl]

The Doctor couldn't kill the Daleks. When it came to pressing that switch, he couldn't do it. I have a hunch that pre-Nine Doctors would have, that the Doctor couldn't do it again after what he had done to Gallifrey/the Time Lords. But it's a selfish choice, like the one to let Rose out of the vault in Dalek. All the humans on earth are going to suffer a fate worse than death is he doesn't pull that lever. He had no idea the TARDIS ex machina was going to turn up.
in fact, Jack's, "Never doubted him. Never will." was misplaced confidence. and then they went and left him behind!