I guess it's an agree to dissagree, because we won't see the full fight to the death, and because of that there can't be a definitive answer, because we don't know if Saskue would have pulled out ama. right off the bat or went with gen. like he did in the chapter, I agree if ama. came out right away it's highly unlikely that Bee can come out of it alive. but we know that bee is immune to gen. because of the hachibi, and could have pulled the same lariat move again. Thats why is hard to argue these "capture not kill fights" because you can always say he wasn't fighting to kill.
However I would like to see that fight

maybe ill write deadliest warrior on spike TV lol
all I can go off of is what is said above is that he failed his mission, he got cocky with gen. and thinking that Bee couldnt move and got a 7-tailed lariat to the chestplate. so if you say bee couldnt have won since he ran away by the same token saskue couldnt have won either since his mission failed so its a draw IMO