Something else to consider is that a bear that appears to be broadside can in fact be quartering away slightly. A bear's anatomy is very similar to a human's and if you aim right at the shoulder on a quartering away bear there is a high likelihood that no vitals will be hit after passing through the shoulder. I had that happen to me last fall, resulting in a piece of shoulder bone at the hit site. The bear was seen two hours later moving okay but another shot was not taken due to the fact that we weren't sure it was the same bear until after it took off. Afterwards we found a little more sign where the bear had been standing. A high shoulder shot would still anchor the bear and aiming behind the shoulder would put you in both lungs.
If the bear happens to be quartering towards you, an aiming point behind the shoulder would still put you at the very back of the lungs and possibly liver depending on which way the bear is facing. A hit behind the lungs through the guts will still be lethal and if the bear is not pressured it will probably bed down nearby and eventually die or at least stiffen up to the point it is incapable of charging the hunter as he blood trails. (Had that happen on my buddy's bear last fall, with the guide and both of us on the blood trail, my buddy was able to finish the mortally wounded bear with a follow up shot a couple of hours after the initial hit).
Unless the bear is up close such as over bait it can be very hard to assess body angle due to the thick coat of black hair obscuring anatomical landmarks.