8 shot tends to get attenuated by air resistance fairly quickly - the victim was about 30 yards away and it penetrated his skin. The biggest danger at that range would have been if it hit an eye or caught too much in the neck where it could have impacted an artery or vein.
Now, if he had been hit by goose load (2 shot) at that range, he would have been much more seriously injured.
8 shot (doves and quail) is smaller than a BB (8 shot is smaller than 4 shot (duck and pheasants), etc.). But there is a lot of 8 shot even in a 28 gauge shotshell.
I'm reminded of when my dad was a kid and the farmer with rocksalt load blasted his legs and rear......Dad always claimed he was stealing corn but my bro and I always suspected the farmers daughter had more to do with it....the farmer had excellent shotgun control, he waited until the range was "just right" to penetrate pants and just a little skin.....