Interesting Technical Situation

[rgncjn]

Watched this situation unfold the other evening at a local high school varsity boys game.

Team A turns the ball over in their front court. Substitute B6 has reported to the scorer and is waiting to enter the game. The center official (opposite table) sounds his whistle, sticks his hand to up signal to the other official to hold play. Substitute B6 is beckoned on to the playing court by the center official.

B6 enters the court and reports to B1 that he is being replaced. During this, the new trail official has administered the ball for the throw-in that Team B recieved as a result of Team A's turnover. Play is stopped instantly when the trail official realizes that Team B has 6 players on the court.

A technical foul is assessed to Team B for having more than five players on the court.

Is this an administrative technical for having more than five players on the court? Is this a technical foul in B6 for entering the court (even though he was beckoned)? Is this a technical foul on B1 for not leaving the court?

The official who beckoned B6 on to the floor did not come in and tell the calling official that he beckoned him on, and instead went ahead and agreed with assessing the technical foul.

When I spoke to one of the officials after the game (a good friend), I asked how they assessed the technical foul. He said that they charged the technical to B1 for not promptly leaving the court. Rules citation?