Firstly, I think you did very well - I'm not sure I'd have been brave enough to have gone on national radio like that, so well done!
I must say though that I was a little disappointed with the segment (not with you). Given the strength of feeling (obvious from the texts etc.) I was hoping for perhaps a 10-15min really productive debate, exploring the issues. However, you got about 2 chances to speak, the other chap the same, and just two short callers, and everyone was interrupted to keep their answers short. Yet afterwards, the presenter was prattling on about nothing - he's now talking about a dog jumping on a piano!
Perhaps my expectations were wrong?
I thought that the other chap was very prepared and drove home the idea of identification/accountability - it would be interesting to learn more how other countries administer this. I also think that you did very well in getting across the idea that we don't think all cyclists are saintly, and that we can all learn how to do things better; and you countered the accountability/insurance idea well with the mention of house insurance.
And, you didn't scream once.
Hope that's useful?