I didn't actually kill the guy. While it was my foot/hand that touched the pin and caused it to tip, it was gravity who then took over, and caused it to tip completely, fall down, and roll. So go blame gravity.

Me, when the bumbling dick missile manages to somehow slip on a rolling pin, I beat them to death with it.

Porbably Person... Idk why but the less sense, more the reason to be the answer.

I say its the tree that grew the wood to form that pin. But then.....who planted that tree..
Nature did it.
But the tree is a part of nature...
So the tree did it....
But nature planted the tree...

Blame science, since it created the big bang, and the big bang created galaxies, and galaxies created solar systems, which created planets and stars, which created the Earth, which then created life, and that life created a tree, in which that tree was then chopped down for wood, which the wood is then used as a bowling pin, and then the bowling pin is placed randomly in a remote location, which happens to be in the middle of a busy sidewalk, which then someone slips on the bowling pin, and thus.. gravity causes that person to fall down, to where they potentially die. And what causes gravity you ask? SCIENCE!!