Saw it Coming wasn't able to counter with while foretold.
Foretold Saw It Coming and had a snow-covered island and a snow-covered mountain untapped. Opponent cast Unexpected Windfall from hand with only a treasure untapped and Goldspan Dragon on the board. No other effects on table to make spells cost more. Attempted to counter Windfall with Saw it Coming and it wouldn't allow it.
You can't cast a spell you foretold in the same turn