Yeah - the video looks like a bug moving across the lens. Not too sure about a silverfish or centipede, but maybe something more like a Webspinner, which is becoming quite common over here these days, or some other variant of flying arthropod:
They are long and fast-moving, and would certainly blur out in the shape defined in the video.
The still picture:
Issues I have with this as an investigator are:
i) No time or date stamp is shown to state when it was actually caught. Comparing the grass area in the top right of both the image and video, and the difference between the rubbish in the still image, and the cleanliness in the video, it is obvious that these captures were taken some time apart.
ii) Only available in a still shot, no video, despite searching all the outlets covering this story. To me, it lacks credibility.
iii) The article states the woman as stating, '
My partner was up during the night and saw it on the camera'. However, it is clearly daytime and an inconsistency to the story presented. If they caught it at night, where are the night images?
iv) In all my years researching the paranormal, I have never heard of a credible black mass or shadow person being captured outdoors in broad daylight - it goes against everything we know about this phenomenon.
In my opinion, this is just dirt of some kind or something else just stuck on the lens. It is too solid in areas and nothing can really be defined from it.