Translation

"Teen shoots self in junk while cleaning his pistol"

Right.  Whenever you see "shot while cleaning" I am sure that at least half the time it's the excuse used when the truth was, "Teen, probably under the influence of some mood altering substance, was showing off around friends with a loaded gun."

Yes people do stupid things while actually cleaning a gun.  Like violate 3 of the 4 rules simultaneously, I am almost positive this is not the case.  (Clearly, if cleaning, rule One was violated as he didn't triple check to see if it was loaded or not, he pointed it at something he DEFINITELY DIDN'T want destroyed, so rule Two, and the finger was on the trigger for the unhappy event... rule Three.  Rule Four sorta doesn't come into it or apply, so lets give him a pass and just award the hat trick.)

Not mentioning the whole 18 year old with an HK.  So the gun is stolen, 'borrowed' from a parent, or gifted by some adult.  All circumstances at least somewhat questionable, in view of the result.

Other possibility... He was carrying his pistol in his wasteband and grabbed the trigger re-arranging it.  Again "cleaning it and it went off" is the story you tell the cops.  After they don't go for the "Sumdood shot me and ran away" baloney.   "Sumdood shot me!" is the best excuse for the kid, after, as he doesn't get in trouble AND he gets to keep the expensive pistol.  You wouldn't expect there to be a gun to confiscate if the mysterious owner and assailant absconded.

He could have been cleaning it.  But my BS detector tells me it's the less likely scenario.