Tell your dad I said hi. :)
It was a little moment that probably only those of us who watch GWB so closely paid any attention to. I think your dad is right. GWB was preoccupied and just turned and walked off, but the limo was in the other direction. The agents quickly caught up to him, and when GWB heard the noise of the gunned engine, he turned and waited. I smiled at the little episode, because usually the Secret Service doesn't let such moments happen.
Given today's events, I have no doubt the unexpected visit by PM Blair in July, not long after the G8 summit, had to do with the early intelligence reports on this plot. Politics aside, the relationship between your Prime Minister and our President is quite touching in a way.