I think the lady was right to ask him to stop, and he had no reason to take offence. He should have asked permission - yours and theirs.

I'm not even a professional, but I dislike being filmed playing or singing (or talking, or eating, or anything else really) unless there's a good reason and I've given permission. I don't like to find I am suddenly the subject of someone else's film. People with video cameras should ask permission before doing this, and not take offence if it's refused.

I know that with mobile-phone cameras, this sort of thing happens more and more, but that doesn't make it right, and there should still be some common courtesies observed when it comes to filming people, particularly if they're well known and could be caught off their guard.

How did the rest of the guests react, do you know?

Marje