Civil registration records are generally reliable. They are created on the day itself or a few days afterward. But not all information in the record is of the same quality.
In my experience, the information about the parents in a death record is the least reliable of all the information you can find in civil registration records. The informant is usually a neighbor, not a family member, who probably never knew the parents of the deceased. They may have misheard, or misremembered. They may have assumed the father’s name based on the name of the eldest son, or may not have known about an earlier wife of the father who was the mother of the deceased.
Taking such information as fact can lead to brick walls, if you can’t find the parents in other records.
When analyzing a record, always make sure to check who the informant was, and if it is possible that he or she made an error. Records with errors in them make a poor foundation upon which to build your further research.