That's the first I heard that story. Lennon himself has been suspected of causing the death of Stu Sutcliffe after the two allegedly got into a fight. Supposedly the head injuries Lennon inflicted eventually caught up with Sutcliffe, who died of a brain hemmorrhage.
Stu & Lennon got ambushed by some tuffs one night in Liverpool, I think, and Stu got hurt, but he wasn't fighting Lennon.
I thought Stu Sutcliffe got his head kicked by a couple of German teddy boys.