Are you serious? Why do I need to know what the issue is? Inadequate picture? The smudge can only be seen at certain angle with the right amount of light on it. It was extremely hard to take that picture.
Here is a video for you. Sorry if it is inadequate for your standards.
Are YOU serious?
Listen, if you're unhappy then of course return it for a refund. Shearwater is a standup company that stands behind their products and has excellent customer service.
Creating a whiny thread on the internet about this says volumes more about your character than it does Shearwater's QCA process or their customer service.