What’s wrong with this picture?

First, a bit about the husband of my GGA Irene Carroll:

• Denson Martin
• born Buda, Hays, Texas 23 Aug 1893
• died Napa County, California 9 Jun 1986
• buried Martin Church Cemetery, Goforth, Hays, Texas

At least the headstone for Denson Martin is in Martin Church Cemetery…

Why do I question his burial location?

Both Denson and Irene died in Napa County, California, according to both the SSDI and Ancestry.com’s California Death Index, 1940-1997. Irene is not listed as being buried at Martin Cemetery. Denson’s date of death is not on his headstone…

What is wrong with this picture?