Why does it seem to me that a reasonable person could have simply reassured all of the involved parties that he was a properly skilled ex-army medic and then they might have left him and his family alone? My experience with EMTs, and most LEOs, is that they are intelligent, reasonable human beings who have to make some difficult decisions quickly, based on limited information.
You know what the EMTs and social workers were thinking? "Protect the child".
I'm a big fan of government staying the hell out of our lives, but imagine what would have happened if that boy had died, or suffered brain damage. Not only would the kid have been harmed, but In today's litigious society who knows if the parent would later blame the EMTs, social workers, etc. and then try to sue.