Friend, I find that post hilarious. Or your signature line hilarious. Or the combination of the two. All of life is risk. Either risk management belongs to the individual, or it belongs to someone else (the government). I think my position is clear, if not well-stated. I believe I understand yours.
At some point, you have to either claim the right to control other people, or you have to let it go. IMO, it is better to teach, even though some will choose wrong. Force vs persuasion. Freedom vs subjection. I have not always lived the principle well, but I stand on the side of freedom. Even with the risks that freedom entails.
Then you will appreciate this quote as it fits what you are saying:
"That the only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is
to prevent harm to others. His own good, either physical or moral, is not a sufficient warrant. He cannot rightfully be compelled to do or forbear because it will be better for him to do so, because it will make him happier, because, in the opinions of others, to do so would be wise, or even right. These are good reasons for remonstrating with him, or reasoning with him, or persuading him, or entreating him, but not for compelling him, or visiting him with any evil, in case he do otherwise." – John Stuart Mill
I agree with you that risk management belongs to the individual... and the individual, the child, in this case didn't have the option to decide risk management for itself...
Once the man on the motorcycle made a decision that could harm another, in this case the child, we can and should, rightfully exercise power over him...
You are correct to champion the rights of the individual, where you are wrong is that you don't see the individuality of the child...