Scary Lesson to be learned

today I realized that just when you think your kids are growing up and learning how to survive, they are not. They are still little kids and impulses are in greater control than their logic.
J goes to a sports group at the park around the corner and for the past few lessons big J walks him there and 45 min later allows him to walk home. Tonight at dinner, J was talking about the "walk" home and mentioned a car was going down the one way block the wrong way.
You know how the kids chatter and sometimes you only half listening?
Well, I half heard that J "told" the man he was going the wrong way and the car stopped and J walked over to the car to tell him it was a one way street...
YOU WHAT!!!???? I screeched! You talked to a stranger? YOU WENT NEAR A CAR? YOU SPOKE TO A STRANGER AND WENT NEAR A CAR?????????
I began to shake inside and the pit of my stomach moved up into my throat as I thought of all the scary horror stories... (I actually can't go on thinking of the worst...)
I think by my inability to hide my terror at the thought of what he did, it scared the pants off of him when he logically, not impulsively thought about what he did.
We haven't let this child play out in front of our house without supervision and now that we have started to give him some freedom and look what happens...
I know, I know, nothing happened. Thank God. I have been thanking and praising God for his protection and love and grace tonight. But I feel terrible that my baby didn't use his head and make a safe decision.
So what if the guy in the car wasn't looking to talk to a child, one day someone might be looking to talk to a child and mine is the one talking and walking up to cars.
It's not like we haven't talked and preached and shown and talked more about the dangers of strangers. Right now it appears we need to talk about it more. and then one more time. and each time they leave the house or my site they should be reminded of the fact they need to be aware of the world they live in.
so what do we do? next sports day, do I allow J to walk by himself again? Do I continue to shelter him from the world? I know he has to learn and I have to put my trust in the Lord and not in myself. But it's so hard...
What would you do?
I need to pray for guidance and strength.