I located the gravestone of one of my great-uncles once, directly beside that of his wife in her family’s plot. Both stones were inscribed with a year of birth and her stone was inscribed with the year of death; his death year was blank. It was not until I visited the municipal cemetery department that I found he was buried in another cemetery altogether–with another woman with the same surname as his.
Always be sure to do thorough research and follow up on anomalies. This revelation led me to records of his second marriage and a whole collection of additional records for his ‘second’ married life.