I guess the impact was not as far forward as it appears in the photo. There was a 3-4” long shard of rib in the chest cavity when he filed dressed the deer.
The bullet did not hit shoulder or leg bones. All were intact. Someone above said it was “failure of shot placement.” I disagree. The bullet entered the chest close to the shoulder but not into the shoulder. That is excellent shot placement. Ultimately, it appears the bullet fragments caused damage to the heart and both lungs.