If someone hit a shoulder with almost any legal firearm and did not kill the deer they must have taken out the near shoulder on a quartering away angle or shot a deer on a dead run such that the shoulder was out in front of the chest. The whole concept of a "shoulder shot" is to take out a shoulder
on the way into the chest. If you hit the shoulder at such an angle that the chest is not behind it, then you are shooting for the wrong shoulder. A quartering toward, or even perfectly broadside hit in the shoulder joint will penetrate into the chest and major vessels enough to kill a deer pretty quickly. There is no way a slug (or muzzy bullet) stops at the shoulder and fails to penetrate the chest at any reasonable distance. Even if it breaks up, there is enough energy there that the pieces of bullet &/or bone will get the job done. There is a reason that bear guides often use slug guns as a backup weapon. They are that powerful at close range! On a quartering away angle, shoot for the far shoulder so the bullet goes through the chest first.
Just because someone thinks/says they hit the shoulder, doesn't necessarily make it so. There is a lot of front leg that can be broken that doesn't overlay the chest, allowing the animal to run away. Just like a fisherman, you can tell any story you want about "the one that got away".
As for ruining meat with a shoulder shot, I would rather they drop & die right there than run a hundred yards before dying. I'll trade a handful of lost grinding meat from a shoulder hit for all the blood shot meat that I get from one that runs a hundred yards before dying any day.