Oh no not another free will thread.

[Mystic]

The thing is "back through time" would mean, past, present, future is some sort of stream that all exists at once. If this is true, then indeed free-will is impossible per the argument shown. He would have the illusion of free-will, but if the future is discovered, he can't choose otherwise, if it's truly a determined inescapable future.

Past present and future is a stream that all exists at once, but think of it as a branching stream rather than a single path.

You're in a canoe going down a river and come to a fork.  You go right.  You get out of the water.  Walk back a mile or so and get back in.  You come to the fork in the river again.  This time you go left.

This type of future you speak about exists not in the sense it's already has been done but it exists in possibilities and probabilities, and some of is set and cannot be changed in knowledge.

The Jinn I believe can temporarily estimate states of the future, but they can never know fully, and they been trying to get accurate, but they will continue only be disappointed as long as they don't submit to the Master appointed to represent God, who is revealed things in summary and then the plan in details as things go a long, and with God establishes and erases what he pleases. 

However if the future is set in stone type future, then that future cannot be changed right, and that is where free-will is impossible.