Low shoulder and high shoulder is both marginal shots. Both have a good chance of missing the vitals if you are forward any at all or low as in the brisket. Im guessing we are talking about the second shot being a follow up shot? If the deer was hit both times while moving through the timber, that tells me the kids is a very experienced shooter and just missed the vitals. I have shot deer on the move and also shot them on the run and I can tell you that I had no idea where I hit them until I recovered them. I’m not saying that you do not know where he hit the deer, I’m just telling my experiences. Shoulder shots can put them down fast if you disrupt the central nervous system. As far as the 30/30, last year I shot a nice buck at about 100yds with mine with 170gr soft points. Perfect quartering to me shot, standing still in the wide open. I put the crosshairs right where his neck meets his shoulders. My favorite shot ever. Squeezed the shot of. The buck jumped about 4’ in the air, spun around and disappeared into the trees. I got down and eased over there and found a few drops of blood where here spun and nothing else. Till this day I never found that deer. I looked for 2 days and watched for buzzards for a week. I have no idea what happened but it did. I checked the rifle and it was dead on at 100 just like it was supposed to be. The only thing I can see is I choked and pulled the shot forward and just went through the flesh of the shoulder, missing the bones and the vitals. I just chalked it up to human error and not the gun. Sometimes chit happens. I said all that to say don’t blame the caliber, blame the shooter. If you hunt long enough it happens especially on deer moving and running through timber.