In my research, I found a timeline reconstruction on YouTube which seemed to show it is plausible the father and son stopped pursuit and the other merely pushed him back in the direction.

Saw another recreation this morning that shows a rather more aggressive pursuit, including the two parties using one another to entrap (falsely imprison) Arbery whether or not they knew one another.

I am open to the possibility this is felony murder. If the father and son were using the other guy (whether they knew him or not) to entrap Arbery, because they killed him (self-defense or not) then that bloodshed is on them... if they didn't have adequate justification for containing him and then lifting the rifle at him.

But the other guy, I don't see the continuum with the guy with the camera with the death. So I personally think while he may have committed a felony in false imprisonment, and potential assault with his vehicle, he is not necessarily guilty of felony murder.