WOW! Great feedback.
The professionals, Not Me, tend to look at the aid you would give and the legal implications involved; an unfortunate necessity in this day and age of lawyers, gypsies, tramps and thieves.
The non-professionals, me included, tend to move faster with a little less thought perhaps.
Some place in the middle for a non-professional seems to be the best approach.
Without being demeaning to anyone, a lot of it is common sense, but not necessarily all that I would have considered prior to reading this input.
I would find it difficult to do "nothing" if common sense and an evaluation of the situation dictated that "something postive" could be done, even if just to warn oncoming traffic.
I guess the main thing for a non-professional to do would be to "offer no advice" to anyone involved in the accident. Speaks volumes in itself.

I appreciate the feedback, good food for thought.

Thanks very much.