Sorry David, I came to the same conclusion as you some time ago. I do not have the marriage certificate but viewed the record when I visited HALS shortly after I started researching the family. Unfortunately in those days I was foolish enough not to note down the details of witnesses and whether or not James signed his certificate or left his mark. I'm nolonger able to get to Hertford to check it out.
Maybe some kind person may be able to check up on the details if they visit the record office? ;D
Laurina