Good explanation Sinann. Yes, I certainly understand that the name given is the mother's maiden name [and very useful it is in a baptism too] BUT it is not also the father's surname which should, in those days, be the same as the child's. It may have been in the instructions given to the transcribers, otherwise if it was a few transcribers who misunderstood, it should have been picked up at the review stage.
I'll let you know when/if I hear back from findmypast.