The first post tells us about the crack. Nine posts later we are presented with another view of the crack with a hole - this was never mentioned previously. Now a photo that doesn't appear to show an additional hole on the NDS seatstay. Was the hole there when you received the frame? I ask because you made no note of it at all in your initial post, and that is somewhat surprising given you're looking to find out if the frame is structurally sound or not.

The only reason to drill a hole at either end of a crack is to stop the crack from getting bigger. If that hole/crack combo was there when you received it and he didn't disclose, you should get your money back.

DD