I don't see why making noise during a moment's silence is not applicable. Both are deliberately going against what is being asked of you (one to stand, the other to be quiet). No need to twist one's self into knots. Choosing to remain seated, let alone going one further and taking a knee, during a national anthem is showing disrespect for that anthem. Its poor etiquette if done by mistake, and disrespectful at worst if done deliberately. Frankly I don't see how its even up for debate. To me the only knot twisting is being done by people trying to claim that kneeling is actually a respectful thing to do. That just doesn't make sense.