A boys first broken pushrod.... LOL

You have 2K miles on it. I don't agree with the "starved for oil" bit. It's getting some oil or you've have more issues and you would have had them within a few hundred miles.
I agree with Replica - have the shop pull the rockers and you should be there when they do it to see what it looks like (and get pics). Have them fix the shaft placement, replace anything that's showing signs of getting hot. I doubt you'll find anything but you should have them check. Also have them check the pushrods for loose cups and that the cup on the pushrods is the correct radius for the rocker. I think they ordered 3/8 radius and it should be 5/16 IIRC. In that case the cup end may get stressed in odd directions and loosen up.