http://www.bbc.co.uk/search/news/stephen_hawking ... nope, nothing about a JW convention.
http://www.bbc.co.uk/search/news/richard_dawkins ... nope, nothing there either.
As I write this, the present BBC News headline page is #15884523, one digit diffferent from Mankelli's # 15834523. That is either an extraordinary cooincidence or symptomatic of a Bogus Statement.