I read somewhere a day or two ago that the fella who was wearing the uniform is actually a bit mentally/physically challenged. Apparently his life's goal has been to be accepted into the Army, and he has failed several times. A local recruiter has befriended him, encouraging him, and told him where to buy the uniform as a way to lift his spirits after failing again.
The poor guy idolizes the military, and he thought he was paying respect. He's playing dress-up in a naive, childlike way, not knowing that it caused offense. Apparently he is distraught over having been confronted. He says that all he wants is to be a soldier, and that if he could pass the exams, he would pack up and leave for basic in a heartbeat.
I'm not sure where I read it. I'll try to dig it up. Sometimes perspective is all.