I heard the same thing.
I'm sure that security is very, very interested to hear that, being that it should be bulletproof glass and all. Doesn't that glass break down and need replacing often?
Fortunate that they only got attacked by a bunch of dumb disorganized anarchists, rather than someone really intent on causing damage.
While the Royal Family does have some heavily armoured vehicles, bullet proof glass, etc. not all of them are. The Prince of Wales and the Duchess were in the Silver Jubilee Car during this incident, which is designed for visibility - that is to make the occupants visible. That was obviously not the right choice given the situation in London at the moment. He should have been (in my view) in his normal car which is an armoured Bentley Turbo R. Somebody obviously decided they wanted a display for the Royal Variety Performance. Balancing the public's desire to see the Royal Family and the need for their protection is not an easy task, but I think a lot of people will say somebody just got it wrong.