You can have kidney failure for a variety of reasons at a relatively young age. It could be genetics, some issue Genevieve had earlier in life, etc.
Maybe in his mind, since he was doing that before he and Eveyln made "peace" over their kid's death, it didn't count. Though I do agree that it seems kind of silly for him to be shocked over all this, after what he has done.
I also agree about getting rid of Rosie's new family. The whole thing is ridiculous. The nephew is like some silent movie villian. The only thing he doesn't do is twirl his mustache while laughing maniacally.