To be able to overlay the images of completely different works and have the lines fit together perfectly is also something common to all Manga. ALL OF IT!
Well, I think there is some truth to this. That goes for Superhero comics as well, since there are so many generic symbols, silhouettes and gestures that are ingrained in the minds of artists working within these fields. Take the classic Jack Kirby pose of a hero dashing towards the viewer for example. How many times have those same lines been repeated over the years by various artists?
Either way, there was this basketball manga a couple of years back that got caught swiping huge chunks of another basketball manga, namely Slam Dunk, which in turn had ironically enough been swiping NBA photos for years. The way I see it this kid is just keeping up with the good ol' Japanese spirit of churning out comic pages at any cost, and making a buck out of it. Good for him!