injured player

[emtp]

Team A shoots and misses, Team B gets rebound, A1 slips on floor OOB on A1 baseline, fast break going other way. Player off the court and does does not appear to be in danger at this time, Team B goes to bucket kicks it out and right back in and scores lay up. Blow whistle stop play, I have coach from team A attend to his player. This a HS varsity game. Looked in rule book for when to stop the game. Couldn't find anything. I didn't stop the game until A had the ball again because as I would observe the player down was getting to his knee and looking down court, not screeming and the fact that he went down on his own. Coach thought I should have stopped the game when team B kicks the ball back outside. Help here for an interpitation and where to find this in the rule book.