Understanding the vulnerability of ASD individuals

My mild-to-moderately autistic son is six-years old and is in Grade 1. Starting this year, his school recesses take place at the same time as the rest of the school which includes students up to Grade 8. That leaves him pretty much exposed to a wide spectrum of much more verbally (as well as otherwise) sophisticated groups of children who, for the fun of it or maybe, on a dare, could easily take advantage of his "gullible" nature, a result of his "mindblindness". My son is struggling verbally and reading body languages and predicting events are nowhere on the horizon yet as far as the level of his communication ability is concerned.
Here's a scenario of mindblindness or lack of theory of mind, defined by autism expert Dr.Simon Barry Cohen. A child on the autism spectrum is walking on a side-walk along a street and he sees a group of boys on the other side of the street looking over and gesturing towards him. The group decides to cross the street, their gestures, facial and body expressions clearly indicating their intent to do harm to the boy. But if the boy happen to see them crossing over, he would have noted only just that - that a group of boys were crossing the street. He could and would not have read their threatening body language and therefore, would not have been able to foresee the danger he might be facing.
Summing it up is a quote by Geoffrey Cowley's article "Understanding Autism," in Newsweek,
"What, ultimately, makes autistic people different? How do they experience the world? Twenty years ago no one had much of a clue. But a burgeoning body of research now suggests that the core of all autism is a syndrome known as mindblindness. For most of us, mind reading comes as naturally as walking or chewing. We readily deduce what other people know and what they don't, and we understand implicitly that thoughts and feelings are revealed in gestures, facial expressions and tone of voice. An autistic person may sense none of this."