Good pics. The top one is particularly useful as it clearly shows the very early stages of failure on the tappet on the right. Even though the DLC hasn't started to abrade you can clearly see the different colour tone in the centre of the face caused by the coating crazing as it fractures.
My guess is that a lot of the people who take umbrage at my observation that they are all going to fail will of looked at their tappets, (Or their mechanic will of!) and seen that sort of damage and either thought it was OK or didn't notice it at all! Make no mistake, that tappet is on the way out too.