My thanks to Bob Smith for drawing this to my attention. The good news is that no one was hurt and everyone got to complete their journey.
http://news.bbc.co.uk/1/hi/scotland/south_of_scotland/7074972.stm
The megabus in question wasn’t the old Olympian pictured on the BBC site but a much newer Neoplan. Infact, I belive this photo is of the actual bus; fleet number 50148!