Yeah, I'm going to have to respectfully disagree there. I have no problem with a team silently advancing on the ABs, but noise that drowns out the haka? No, it shouldn't be allowed. I do think that's disrespectful because it's like an audience that heckles over a public speaker. Heckling = disrespect, and so singing, chanting, yelling, or anything else during the haka would amount to heckling, which is a disrespectful action.
das
100% my view. There are plenty of responses I love, advancing on the haka like France or not moving like Wales. All great - but singing over the top of it, especially when it is 23 people performing to 80,000 is simply disrespectful. But again I'll just be called precious.