The issue is that you can't guarantee there won't be harm, and by doing it and not stopping it in the future, you are inviting others to do similar stuff. And probably to one up each other.
And eventually there will be an accident and something important will be lost forever.
Y'all are really out here acting like "no harm no foul" like you'd be fine with your toddler running into the street because "nothing happened!" This time. Next time, a semi could be speeding by.