User blog comment:Thailog/Ep. 206 "Bloodlines" discussion/@comment-5145408-20120604165540

regarding the future staying the same, you end up with two possibilities...

1) The event that Impulse changed was not the actual lynchpin event that caused the future

(maybe they thought it was. or maybe Impulse just wanted to save Flash's life and wasn't trying to save the future itself)

2) That time is immutable (a concept used by one of the producers of this show on a previous show that he produced) so something else happened or changed to cause it all