Matchpoints.
I was North on the auction above.
As soon as the final pass had been made, South led and faced ♦K.
The TD was called and she explained the options available to West. West elected to accept the opening lead, table her hand, and make East declarer.
As North, I had an inference that would not normally have been available from my partner's choice of opening lead. Partner had not led my suit at trick one. It wasn't a case of him having too many hearts (as he had failed to raise), so he was very likely to be void in hearts.
If East had been the first person to bid spades, then my correct defence would be to win ♦A on the first or second round and then switch to a low heart, awaiting making ♥HAQ in due course.
Am I allowed to take advantage of this inference after the lead out of turn?
If I do win ♦A and switch to a low heart, should the TD adjust the score?
Please give Law references when answering.