Last out of inning

[Little Jimmy]

I understand the idea and application of the 4th out appeal. But how do I know that the defense is appealing? On a missed base or leaving early situation it's generally conceeded as common knowledge that a throw back to that base is an appeal. But on this one I'd need to hear something verbal from someone. What's the level of play? 12U rec or 18U club team? I could easily see some kids not knowing what the out count was and throwing over to first with no appeal in mind. Am I awarding them for being lucky of for being smart?