Your scenario makes sense except for the term “sharpshooter”. I don’t know anything about the military, but I have a hard time picturing someone just in boot camp being trained as a sharp shooter. Wouldn’t that be some specialized training pursued after boot camp? (And I apologize to any Marines if “boot camp” is the wrong term.)
Of course, we need to consider that in what today passes for journalism “sharpshooter” could have all sorts of definitions.
The Marksmanship badges are Expert, Sharpshooter, Marksman in descending order. You must qual. Sharpshooter isn’t hard to get if your eyes work, and you don’t forget where you are with your ‘dope’. Boot camp Marines can shoot, do not doubt that. Marksmanship instruction is very important to the Corps. This knucklehead likely scored Sharpshooter on the range.