I have been coming across birth records that list birth dates that conflict with FindAGrave. If the birth record is consistent with father's name and mother's given name, along with birth location (birth, not baptism) and it conflicts with FindAGrave, I have been leaving suggestions for FindAGrave indicating the information on the birth record, along with birth location if listed.
And there have been times when the year on the headstone is not consistent with the birth record. If the person was born in say 1820 and a friend or family member is expected to report the death in 1900, they may not know the year and give a guesstimate to the undertaker say 1874, which makes the death record incorrect, the headstone incorrect and the FindAGrave incorrect (they don't check for birth records). So, while it takes time from my wiki-sourcing, I do leave suggestions for changes on FindAGrave when I come across birth records that are inconsistent with FindAGrave. I've actually gotten a couple of replies indicating they changed the birth date based on the birth record!
My issue is when I come across birth records for the SAME family member and one birth record lists say 10 Jan 1831 and when I check the next birth record for the SAME person it lists 10 Jan 1832! Case in point, Col Jeduthan Baldwin.