While not an exciting story as yours, I recall we had two hills by me (recall I'm in NJ suburbia) that were accessible in a patch of woods that was still off limit to development. No longer the case, but that's a side-bar.
The only problem was both hills faced each other. "Chicken" anyone?
I remember one head-on that would, nowadays, get you to a hospital and lawyers involved.
Like with you, we just realized that it was just kids being kids. Felt pretty woozy for a while but it passed.
No tattling to mommy or the other guy's mommy. No guidance counselors and shrinks needed, thank you very much. Just kids being kids.
We've sunk a looooooong way since then. That's why I love these old Calvin and Hobbes repeats. The last real American kid depicted in here (even if he is a total PITA!!!).
Now the cartoonist would be charged with child endangerment!