Speaking to a coach

[JetMetFan]

Here's are NFHS 9-7-1 and 9-7-3

A player shall not remain for three seconds in that part of his/her free-throw lane between the end line and the farther edge of the free-throw line while the ball is in control of his/her team in his/her frontcourt.

Allowance shall be made for a player who, having been in the restricted area for less than three seconds, dribbles in or moves immediately to try for goal.

Since there isn't a height allowance in there...

If the kid is still in there after 5-6 seconds it's tough to argue he's not gaining an advantage, regardless of height. Put it this way: his height didn't prevent him from getting there in the first place, did it?

As for speaking to the coach, you should know as a former coach yourself the less you can say, the better. If you'd stopped with "Coach, I didn't see him having an advantage" the yelling probably stops a little sooner. He may not have liked it but he might've moved on.