I have an ancestor called Henry whose father was definitely Andrew, yet on Henry's marriage cert (and parish marriage register) his father is recorded as Henry also. I think this must just be a clerical error.
On the other hand, do not be too quick to jump to that conclusion. Early in my research I thought, with good reason, that the father of one of my ancestors was Thomas. When I got her marriage cert it turns out her father was James, and I'd been tracing the wrong line for ages.
Alexander