I think time in the linear way that we see it, doesn't quite give the whole picture. Think of it as ripples in a pond. Normally the pond surface is calm. That's your "predestined" life, if that's what you want to call it. When you drop a stone into it, ripples carry information about the change outward. I think the same thing happens when you toss destiny to the winds, ripples carry data outward (only much faster than in a pond) and things automatically "realign".
What I'm talking about is known as "field theory" in physics. Might want to look it up.
PS: If anyone is interested in a physics-oriented metaphysics discussion, I'm game.