What a weird thing to happen.
You should have gone in an ordered a dry bun put a load of ketchup and mayo on both halves.
Then gone outside and if he charged at you waited until he was at arms length slapped the first half in his face.
Then if the parent / guardian complained you should slapped the other half in his face saying "keep the little fecker on a leash".
Any one want to come for a macdonalds.