I've seen a few references to a John Robertson, who apparantly was credited with shooting down 12 Bf 109's while serving as a Wellington rear-gunner. His grandson published a few facts about his life:
http://carol_fus.tripod.com/raf_hero_jrobertson.html
But nothing about his claims.
Does anyone have more information ?
As far as I can make out Robertson served with 99 sqn during 1940 and 108 sqn (in North Africa) in 1942. But both times primarily on night operations.
So how does the claim for a dozen 109's fit in ?