Talisa's being from Volantis does serve as a good set up for Season 5, now in retrospect, and also Dany's future plot line of breaking the slave trade.
Odd, the two boys who were killed were mentioned earlier in the season as the orphan boys Bran sent to help the aging farmer and his wife, twice. Now all of a sudden the orphans have gained a father Theon wants to pay off? Sloppy. Very sloppy.
Not only that, but he was originally a shepherd, not a farmer.
I will hurt you for this. A day will come when you think you are safe and happy, and your joy will turn to ashes in your mouth, and you will know the debt is paid.