musser zoger -“Neither. Since he is 12 years old he isn’t a bar-mitzva and by definition is patur from mizvos, although his parents have a chiyuv to be mechanech him in mitzvos.”
Wrong on both counts. Some people say the Chiyuv of Chinuch is a D’rabbonon on the Kid themselves. And either way he could still get the Mitzva of Kiddush Hashem because of GODOL Me Shemetzuva V’oiseh Mehme SheAino Metzuva V’oiseh.