Yeah.. sounds like an error on their part. If it wasn't punitive or a failing withdraw, there shouldn't be a problem. I had one W (decided after a couple weeks that the class just wasn't for me), and it was not held against me by LSAC.
When I visited UCI I wore black jeans, blazer, ballet flats and was by far the most dressed up. The guys wore just t-shirts and shorts (or jeans) w/ tennis shoes and there was a girl in short shorts and a normal t-shirt lol.