The media is divided, some say it was a stunt, others believe he was showing his emotion for a change. I've read the excuse on his blog and don't believe him.
All things considered, I think his 'pause' could have been his conscience catching up with his mouth. We all have a conscience, just some suppress it more than most. Mr Campbell is one of these people but today his conscience gained superiority. Not for long though, not with a spin merchant such as Alistair Campbell.
I don't need further proof that the man doesn't believe what he says.