I stayed to watch the V game tonight and witnessed not only a warning for reaching through the boundary, but two technicals for reaching through after the warning. All by the same player. The first T was on the subsequent throw-in after the warning.
Early in the 2nd half, the other (non-warning-giving and t-throwing) official even talked to the player before a throw-in about not reaching through the boundary and appeared to go to some length to ensure the kid understood the rule. But the kid picked up another T for it near the end of the game.
It's my understanding that this is a TEAM technical and not charged to an individual player.
NFHS 10-1-10 Team technical...Art. 10... Following any team warning for delay, commit a violation of the throw-in boundary-line plane as in 9-2-11.
Both T's were charged directly to the player, and the second one resulted in his 5th foul and disqualification, though the official didn't seem like he was going to DQ the kid for getting a second T, not until the scorekeeper signaled it as a fifth foul. I didn't stick around for the post-game, but I wonder if they discussed filing a report with the state for the kid getting DQ'd on technicals.