No. The man was ASKED not to do something that was clearly inflammatory and very well could have serious (violent?) repercussions. Nobody forcibly stopped him from doing anything. People spoke out against it and tried to reason with the man, which is completely legal and appropriate.
As far as the Brit kid... many of the comments here have pointed to the BBC article, which says he used threatening language. Threats are not protected by free speech. I think the whole thing is silly, but if he did make some kind of threat, the response is not unreasonable.