Originally Posted by
Rydin
True.. from what I've seen, one of the major limitations of the "Echo" is that you can view the past but you can never change it... I think they wanted to stress that the echo isn't time travel... it is only viewing a persons memories...
If you used the echo on me... you'd see things from my perspective, and you'd never see anything that I didn't see
Edit: Unless they pull out the Jake Gyllenhaal "Source Code" / Denzel Washington "Deja Vu" deal.... where the main character is told he can only view the past and can't intervene or change it, and he ends up finding a way to do just that