A bloody nose can do that. One of our sons was a bleeder in his middle school years. The slightest knock on his nose and hed hustle to the bathroom with his cupped hands full of blood-if measured it would have been close to a full cup and blood would still be flowing. The bathroom would look like a murder scene-blood everywhere. This happened often enough (wrestling and football are our familys sports) that none of us blinked an eye and I worried more about the new carpet than him. He just made a plug out of tissues and went on with his day.
The amount of blood on the sidewalk might not indicate severe injury-especially since the photo showed them attending to the boys face.
I coached high school and college football for several years...I’ve been in fights and seen fights...That’s most blood I’ve seen ever for someone as young as a middle school child...
Also, my whole point earlier was that with that much blood I doubt there was an “immediate” stop by the policeman...