What's sad about this is the assumption that you would get sued
if you help... thus... do nothing. A problem with the law, maybe... a problem with the
application and
interpretation of the law? Definitely.
Heck, some policeman got in a bit of a spot here for allegedly holding some girl's breast during a rescue operation. It was ruled incidental and accidental and never went to court. That's how it should go.
But, forgive me, I can't buy into the mindset where you think about the legal danger to yourself before you think about doing the right thing. It just seems so...
American 
...when we Filipinos don't stop to help, it's because we're afraid guys with AK47s are going to jump out of the bushes. Either you care and you do something, or you don't. Consequences be damned. It's pretty simple, actually.
But in this case, the guy should have honked his horn, notified somebody... anybody... that "hey, there's this kid wandering around!"... would have been the least involved, least possibly litiguous, and most sensible thing to do. I'm pretty surprised that he actually came forward and confessed to not doing anything... if he didn't care enough to call for the police or some help, he should've just driven away and forgotten about it.