Sid,
I would be very wary of believing what you read in the newspapers - especially when you know something about it yourself "Intercept in 6 minutes over London from Lincolnshire" - I don't think so..............
The transit time MIGHT be 6 minutes but all the other bits need adding in too.
As pilots, I wouldn't speculate too much about this on here - some potential uninvited future pax might be listening.