Saw one similar to this in a small fry game. Long pass, two kids go for the ball, one gets it, the other misses, slips and falls. Two seconds later (literally), kid A scores then whistle. Kid B still laying on the court, turns out he had a concussion. Very wobbly as they helped him up.

I would have to be there to really know. Likely I would not blow the whistle since immediately the team scored. I would stop play after the score if the kid did not get up very quickly. I am not a doctor and I do not think in 2 seconds I can evaluate how hurt a kid is at this point of the play.

Peace

Unless I see blood, an unconscious player or someone who could get hurt by being in the way, keep playing. The closest official, usually the center or trail, should immediately move close to the player. That tells everyone that you see the player and are aware of the situation. Wait to the ball is not being pushed up the floor, or until a shot is taken. Then, kill it.