The Tenth Doctor said something to the extent that saving Galifrey would be changing their own personal timeline.
Also when the Doctor's are explaining to the Timelords their plan. Both the 10th and 11th state that the alternative to freezing Galifrey in a pocket universe is burning and that they have already seen that happen.
You analyze the Bad Wolf macguffin and it's apparent that she is there to change history and influence the Doctor's.
Bad Wolf opens time tunnels to allow the 3 Doctors to interact. After showing the War Doctor his future selves. The War Doctor still resolves to use The Moment. The Bad Wolf interrupts him and lowers whatever barriers that have the events of the timewar timelocked.
With the timelock no longer a factor. Eleven is allowed to put his plan to save Galifrey with his past and future selves across time. I think it was way back in "Father's Day" where the Doctor addresses why he can't go back and change events of the timewar to even save his family. The events were timelocked and unchangeable.
I recently found this little chestnut, where Moffat affirms that what happened in TDOTD was changing events.
"It was the plan from the start – all the Doctors… all the Doctors will fly in to save Gallifrey and change the timeline"
http://metro.co.uk/2013/11/25/steve...h-anniversary-was-the-plan-all-along-4201331/
Doctor Who plays fast and lose with it's time travel rules. If this was Star Trek we would say that the events of TDOTD created a parallel universe. Where a lot of the events will be the same but different slightly going forward. Sort of like ST09. However, we are not going back to relive the events of 9-10 and 11. I don't think we're supposed to analyze things too closely with regards to Dr Who. Now that we are past TDOTD we can say that (for 11) there was one timeline where he did use The Moment, and another timeline where he did not.