A repeater squeeze to make 6NT

When my LHO led the King of hearts against 6NT, I won the Ace and returned the Jack. LHO took this trick and retured a heart. As I won this, pitching a spade from dummy, my RHO was squeezed in three suits. Hoping that his partner held the spade Jack he came down to the doubleton queen. Now I cashed two top spades, and after a few rounds of the minors, revealing that RHO has 4 in each of them, crossed to my hand to enjoy the spade Jack, and he was squeezed yet again in clubs and diamonds, and he conceded.

Let us look at a possible defense. If LHO wins the HJ, we have seen that the repeater operates.
What if LHO ducks the HJ? Now I have on top two hearts, three clubs, three diamonds, and two spades only but, since RHO's hearts have been extracted, I play four rounds of clubs throwing in RHO. He has to concede a eleventh trick in Diamond or spade, but there seems to be no twelfth.

Can anybody find this duck of the HJ? Well, there was a Bridge World hand like that in Swiss Match Challenge where at trick two a refusal was indicated for the same reason.