An unusual first or middle name of an ancestor could be a significant clue. Or it could be a name that your ancestor chose for their child on a complete and utter whim and one that has no bearing on the family history other than the fact it was chosen "out of thin air" as someone's name. That "error" on a death certificate could have been an inadvertent error on the part of the records clerk who got your ancestor's record mixed up with the one he had just completed.
Sometimes in our attempt to find information we assume things are more significant than they are.