playtime
The issur is only to go to sleep on your back or front. If it happened while he was sleeping there is no issur. I dont know where it says you have to wake anyone up who you find sleeping that way. Personally I think if you don’t know halacha, don’t know how to present halacha and explain why we do the things we do, and can’t figure when its necessary to say something and when not you have no business being in Kiruv. In fact you probably will send them back off the derech.