I replied before I read your second post. OMG - your poor DS, even a child without his difficult issues would be upset! Was the police officer really necessary!?
Hopefully his teacher was acting "in the moment" due to his upset (as we all tend to do) and will realize that he needs to modify his behavior to help your DS. Since you already have an IEP, you should be able to modify it as needs arise as demonstrated by this unfortunate incident. The lack of a formal Aspergers diagnosis should not hinder you if the traits are otherwise clear although you might need to "bulldoze" your way a bit. I would put in the written request for a meeting to modify the IEP sooner rather than later.
Unfortunately, there really is no way to teach that type of decision making. I don't have an aspie kid, but DS does have similar issues with good judgments, for lack of a better word. I keep explaining after the fact and teaching examples, which probably doesn't do a thing for him. Oh well, it is heartbreaking but you can only do your best.
