The bullet spent a lot of energy when it hit that shoulder bone, impressive blood shot/shattered bone some even made it to the backstrap. I am not knocking it as it did a tough job and I have had deer run that far with similar hits and more powerful rifles.
I think that this is the explanation. IME BTs from .224" thru .264" are generally a little more fragile than those of a larger diameter when it comes to busting bone, but they generally perform great on behind the shoulder lung shots. The long run after impact seems like an anomaly, but who knows. If the bone splinters had traveled down and back instead of upward they probably would have shredded the lungs and resulted a much shorter run. Just a bad outcome from what should have been a good shot, kind of like in bowling when you hit the head pin and get a 7-10 split instead of a strike.
