To flashforward or foreshadow?

At our last meeting, I said that flashforward (think of it as the opposite of flashback) is not the same as foreshadowing. I would like to expand on this using information from the book I also mentioned.

According to Jon Franklin in his book 'Writing for Story' "flashforward is a woebegotten technique that usually goes something like:

Joe chose to go to the prom with Alice instead of Sue. In the future that choice would come back again and again to haunt him. But now he was much more attracted to Ann."

Franklin says "the flashforward is most of all intrusive, because it has the effect of the writer's telling a secret, sotto voce, into the reader's ear. Like any other intrusion by the writer, the flashforward reminds the reader that the story is an illusion and thereby destroys the sense that the story is real."

He goes on to say that a professional writer may use flashforward perhaps three times in a lifetime and he suggest that as such editors and critics automatically assume the writer who uses flashforward is an amateur. If he wasn't he or she would have foreshadowed instead.

So if that's flashforward how does foreshadowing work, at least according to a Pulitzer prizewinner?

Of course it's more complicated, but I'll sort out some of Franklin's words and post again later.