Jason, I said the majority of the lungs are behind the shoulder (to the left of the shoulder blade on your diagram)but there are lungs under it. By under I meant on the other side of the shoulder you are shooting at.
I shot a deer at a slight down ward angle and perfectly broadside. The arrow hit both shoulder blades. The deer ran about 20 yards and when I gut the deer the broadhead hit both lungs.
I have never feared a deers shoulder or ribs. The only deer I never got a complete pass through on was my first deer with a long bow when I was 14 and I have hit a lot of off side shoulders and some front side shoulders since. Just my experience.
I am not saying aim for them on purpose but if it happens to me like it has I am not going to worry.