In a nutshell, during the course of a counter-terrorism operation, the day before the operation lots of frenetic activity, one of which was for me to go to Number 10 and brief the Home Secretary and the Prime Minister and other officials along with the Security Service colleagues. On that day I was handed a briefing note that was -- should have been prepared the night before. There were logistical problems that day, it wasn't prepared until the morning. It was handed to me in a paper folder, which was unusual, and I guess a consequence of the delay. I read it in the car. When I stepped out of the car, I realised I hadn't put the top sheet back in the paper. I literally saw it as I got out the car, turned it quickly, but there was a photographer somewhere, it would appear, with a pretty good lens. It appears I got snapped and some of that was visible.
It didn't have hugely sensitive data on it, but it had some -- I think an operation name and some roles, but I don't think it revealed a lot of operational detail, but it did reveal that some kind of operation may be about to go ahead.
I later found out, about an hour after I left Downing Street, that I'd been photographed and was very surprised to learn that whoever took it, or someone, had put it on the web, World Wide Web, so I realised the operation had been compromised. I was then focused on how to mitigate that problem, and a decision was taken to bring the arrests forward, which was achievable, and actually went quite smoothly, but it was obviously inconvenient and difficult.
And then at the end of the day I sort of turned my attention to the consequences of that momentary lapse and what I ought to do about it.