Virtually all Mks of Canberra, except, of course,
PR 9s and BI 8s had the winding handle for releasing the main door in an emergency. The only problem for the Rhumbold seat crew was if the gear was down, rolling out of the door meant an immediate impact with either the undercarrieage or the door.
From dim memory, I seem to remember one of the ground crew at Wyton, had to do exactly that (with the gear up) and although unhurt, landed in the middle of Grafham Water. Pilot and Nav banged out and were also unhurt.