Data on a death certificate is only accurate as the knowledge of the informant. So it is possible the death certificate data is incorrect, but I would keep it in mind it could be correct. It is possible there was another John Murray that died on the same date, but it's not likely they both died in the same place. Is the address consistent with what you know about your John.
I actually found a case of a person's death certificate having the wrong first name for the father only to find his 5 siblings' death certificates indicate the correct name. When looking for their death certificates consider that death certificates for some states are online for free.
As I mentioned his obit may be helpful especially if it lists surviving siblings. The siblings obits can also be helpful for the same reason.