[greymule]

Guy rounds 3B and pulls up lame. Halfway home, he falls to the ground, clutching his hamstring. Call time out?

Without the injury, he would have been safe. But with it, he's a dead duck. Are we supposed to award him home?

Two outfielders collide and lie apparently unconscious on the ground. Do we call time out as the ball scoots away? Do we then say, "I guess that's a triple"? What if another outfielder immediately snags the ball and fires it in?

To me, the play doesn't stop because of an injury, but you do call time at the earliest possible moment. No waiting to see whether somebody makes a late break for the next base. That will rarely be more than a few seconds. In the extraordinary case of someone getting a deep gash or suffering a severe blow to the head, then yes, immediate time out and later do the best you can sorting out the play.