>>But I'm getting the feeling that you haven't seen any of this behavior? How about your kids - do they report any kind of disruptive behavior from this kid?
>>
>>
>No. We were only seeing him for ~ 10-15 minutes in the car. In the yeshiva each kid has different person to teach them, so they didn't see him there a lot also.

I doubt they would talk to you, but you could try to discuss the matter with his yeshiva instructors? Explain why you're concerned, etc, and see if they've seen any type of disruptive behavior.