I choose not to answer the one about the handcuffs. ;D I don't think handcuffing is the worst thing that can happen to a person, by far, so I'll let it go at that.
I don't know the specifics of this child, and what special needs he specifically has and I guess it's not really the public's business so we may not hear.
I don't think "sensitivity" is all it's cracked up to be, all the time. Sometimes being overly sensitive leads to overly sensitive - ie, generally unhappy children.
In the last half hour or so, I've been thinking of the ways I've reacted when my kids have been unfairly treated. One time we were at a private park and my son and his friend were chasing each other around and a peacock got in the way of their game and the poor peacock shrieked and flew off. They were being a little rowdy, but it was an outdoor park after all. So the owner came up and reamed them both out, yelling in their faces that they would be kicked out if he ever caught them harassing the animals again, and he doesn't tolerate cruel children. I was sitting at a picnic table 20 or so feet away with other moms. I had seen the whole thing. My son said, meekly and respectfully, "we were chasing each other and didn't see the peacock". The man yelled again don't let me catch you doing that again and stomped off. The kids came to the table, crestfallen and with tears in their eyes, and I said "you did the right thing. You said respectfully that you weren't chasing the bird, and you weren't. But can you see from the owner's viewpoint? Can you see he thought you were being mean to his beloved birds?" And they got it. Another time my much older son, a junior in high school, had this horrid spanish teacher who called a conference between me, my son, and the principal to deal with my son's horrible lying behavior. The woman was a nut, and may have been struggling with mental illness, I don't know. At the end of a very awful meeting, where my son was respectful the whole time, the principal asked after the teacher left if he wanted a reassignment to another teacher. He did. On the way out, I asked him what he learned from this whole thing and he said well, I think I learned Mrs. Lenore probably wasn't gettin' any sex. I laughed so hard.
This is already way too long but I thought of about 5 more incidents where my kids had to deal with unfair treatment, and recover. How will this boy learn to recover, if he's not told what he did was wrong, and next time don't punch at a cop?
You know what they say - what a parent can do that helps their child most is not what they do for the child, but what they teach the child to do for themselves.
Again, I don't mean to sound like I'm blaming this child for being handcuffed, but rather am dismayed that he's not expected to be able to pick up and move on from this with coping skills.