I spoke to the guy over the phone after I found the issue. There were other issues with it too. There was rust and putting under the grips on the frame, hammer, and sight track. I was able to remove the rust but the pitting on the grip of the frame is there and on both sides. It doesn't affect anything and you can't see it once the grips are on.
The seller, Brad, is not a gun guy and doesn't own any guns. His father-in-law recently died and left him a bunch of guns. He just wanted to sell them to get rid of them.
I offered to mail his FFL back the revolver. He declined and said I could have it for all of my trouble.