Lack of Freewill doesn't mean lack of choice

I’m a bit confused. How can something in the future be given as an explanation for a present event?

This also is counterintuitive to me. Isn’t there such a thing as information loss in physics? For example in mathematics, I think if you multiply two nonprime scalars and hand the result to someone else, that person will not be able to determine from the result exactly which two scalars you used. They can only produce a list of pairs, and guarantee that you used one of the pairs from the list.

~Max