Thank you for your reply Richard.
It seems that my best chance is arguing that the CCTV footage does not show the presence of any signs prohibiting the turn. I have found two cases where the adjudicator allowed the appeal based on the fact that the CCTV evidence was insufficient due to the lack of visible signs and the post-event images did not remedy that defect because they are not contemporaneous (2240276019 and 2240411930).
Any advice on how to properly argue this point, or potentially any other, would be appreciated.
Also, just to make sure I am not miscalculating, if I have 28 days after the service of the NOR to appeal, it I have to submit it at latest on 19 February if the NOR is dated 20 January, correct?