How would you pre-game or handle this play if it occurred during your game?

3 man crew

1st situation: Trail is on ball as it is dribbled (no closely guarded count) or passed below the free throw line extended on the C side of the court. Trail goes off ball and begins to closed down as L begins rotation. Trail notices ball bounding toward the division line and it is clear that it is going backcourt. Trail and L abort the rotation. The C is not giving a deflection signal. The ball is not contested out near the division line. The trail has no clue what propelled the ball backcourt. What does the trail do if the offense reaches the ball first in the backcourt? Call a violation? Or, play on and let the C call the violation, if any?

2nd situation: Same as above except this time opponents are racing to the ball out near the division line. The ball is touched first in the backcourt by the offense. Now, the trail still doesn't know how all this got started and the C doesn't know what happened out near the division line. How do you get these 2 pieces of the puzzle together? Put a whistle on it and talk about it? Play on and talk about it at halftime?

Mulk

"Tip signal" maybe?
 

Unless the Trail saw something for sure, they cannot and should not guess. The C can call the violation if they know one took place. It happen in their primary and the division line is their secondary.

Same as above, you cannot call a violation on a guess. The trail also can see the ball if the ball is in the C's area. For one, they would and should still have the ball until the C picks up the ball. And unless there is just a whole lot going on in the Trail's area, not sure why they would not have any idea of how the ball got to the division line. Granted, they might not see the entire play, but they have to come to some kind of decision. And unless they know for sure there is an backcourt violation, I would not call won. But you could talk about signaling a tip to let your partner know you would not have a violation. But that is between your assignor and the philosophy of your group.

Peace

they would not how the ball got back there because they were watching a screen taking place or watching a cutter come clear in their new primary.

Your solution to the first situation is right on. The second? No effort to piece the 2 bits of info together?

You never made any comment about a screen or no screen. You wanted to know what should happen. If the Trail has no competitive matchup in their coverage area, they have to extend their coverage.

But the Center can and I would want them to call a backcourt violation if it is obvious. Better the C call something and the Trail guess. If the play you decribed is worked properly by the officials, the Lead should be rotating or is in the process of rotating. If all we are talking about is a pass, I know I would be watching the pass completion to some extent until my partner picks up the play. Not sure whatelse you need to know. If you are having a problem with how to really deal with this, just ask your assignor, evaluators or mentors. If you pregame this, I am sure your partners will have some idea what to do as well. Come to some kind of consensus and do that.

Peace