Yes I know - the tutorial makes a point to delete the camera before finishing the scene file but I forgot to do that. Do I have to delete the file and make it over again?
By experimenting I found that I can expand the ‘Scene Graph’ in game.scn, select the camera, and just hit ‘delete’. That instantly crashes Xcode but when I restart Xcode and open the game project I see that the camera is gone. That’s kind of heavy-handed but it works.