Well, I've never interacted with people with autism, nor do I know how their behavior is handled. Although it's true that a naive person is prone to being deceived, especially when there's no malice in their mind, like when an older child asks a younger one for lunch or crayons at school, promising to return them later, but that never happens. I heard a saying: "Expect the worst and you'll be right."
Naivety, inexperience and ignorance are all kind of the same, aren't they? I have worked with quite a few people on the spectrum at different levels, and some who have put in the effort have been able to overcome a lot of the challenges, by learning how to cope with them, instead of avoiding facing the challenge.