Doing the right thing doesn't always march to a drum beat.
It's pretty easy to be self righteous when you're not (as) subject to the same accusations and the resulting personal destruction that will follow.
DO what needs to be done in plain view. I'd give the kid the shirt off my back (if need be--I always carry extra clothes with me), flag someone down and get the police there.
Although it would be colder for the kid, they'd be out in the open the whole time, in plain sight.
Any intimation of anything improper would be met with outrage, immediately.
Unfortunately, this has become a hallmark of our culture, to first blame those who help. (Just look at what was done to Richard Jewell.)