Some interesting and well laid out points by several people. I am only going to touch this one

It could be. It could also be that he feels or at least that he at a time felt a push to show off in the presence of Orianthi. Ori herself has clearly taken several steps back in her own playing this year and maybe this in turn could be because she doesn't want to push too hard. She really isn't even a shadow of herself.

I certainly hope it's no terrible disease and I can't believe that since Richie seems awfully content out of stage. But it is a frightening thought.

I still think it is most likely the simplest scenario: Richie doesn't practice and he is thus sloppy. Ori has stopped practicing as well or at least reduced it drastically. She is no rhythm player to begin with and it takes a certain talent to be a good rhythm player anyway. The end result is Richie that is ok with the level he plays and sings. In fact most people in the general public seem to be all right with his performances. Maybe he doesn't even feel the need to practice even if he does give it a thought, which I doubt that he does. RS and Bon Jovi fans that expect better of him as well as guitar fanatics are facepalming hard because both Richie and Orianthi are underperforming. Right now I am of the opinion that Ori is the one that is further away from her normal level because she used to be very solid night in night out while Richie has been a bit of a hit and miss for years.