I'm not sure what you mean by reversed. I just checked a few of my other zipped coats and both my Barbour and my Isaora have zipper pulls on the left side as well like the Document. I have a Columbia jacket with it on the right. I know men's coats always close left over right, but I didn't realize there was zipper side I guess. Do most coats put the zipper pull on the right or left? I would think on the left makes the most sense as most people are right handed and would be using their right hand to guide the end into the pull.
I think that generally the convention is that men's coats have the zipper pull on the right, and women's have it on the left, but I don't think I own enough coats with zippers right now for me to say definitively. I do know that every time I go to close it my right hand reaches for the zipper pull, so I'm certain that the majority of coats I've owned have had it on the right. It's one of those motions like tying my shoes, where I've done it so many times that I don't think about it.