Yes Jerry, I believe you're right. I'll post updates soon. I've been on other projects.
Take a look at the "failed" pump picture. That little wear spot is only on the edge of the arm. Upon close examination I found that the three leaf stack that makes up the pump arm isn't put together correctly. The three leaves aren't even with each other on the mating surface (about 1/64th off) so the leaf at the rear is the only one making contact with the cam.
I intend to check the entire cam lobe, however to be sure.
