So what? England is a free country with the freedom of speach. If they invite a politician who is known as not very much liked they have to expect reactions of the audience.

The day after the event someone explained me that this politician is one of the politicians who is responsible for supporting Bush with the Iraq war. I'm sure if Jon knows this he more than agrees with the booing.

It's not that the booing took away something from George Martin. The booing only was when this politician entered the stage and it stopped when he started to talk about George Martin, even if he had to re-start his speech after 2 words or something.