Magical Thorn and Needle Worm

[HorusMaster]

Does the effect of Needle Worm discarding the top five cards of the deck count towards damage inflicted by Magical Thorn?

I argued that since the cards are not in your hand when Needle Worm's effect resolves, then Magical Thorn cannot inflict damage.

Was I right or did I get cheated by a judge's decision to allow Magical Thorn to inflict damage?

 

[harvey locust]

TextWhen your opponent's card(s) in his/her hand are discarded to the Graveyard, inflict 500 points of damage to his/her Life Points for each card that was discarded.

FLIP: Discard 5 cards from the top of your opponent's Deck to their Graveyard.

you were robbed! those cards are never consider to be in or part of your hand.