Re. 3D nerve palsy, not sure if it is not artistic liberty. But if not - if he is young, it might be congenital, due to birth trauma, or acquired after trauma. With advancing age, other diagnoses, such as aneurysm, stroke, multiple sclerosis, or myasthenia gravis could contribute.
Re. OCD. The loop is very short to tell with certainty. If he makes this odd movement with every second step, as it seems to me, then, OCD is possible.
With OCD, expect a different array of comorbid illnesses. Tourrette’s disorder, tics, ADHD, anxiety, and similar group of issues.
If the locals know him, it would be interesting to ask them if their POI had OCD/Tourrette’s/ADHD at high school. I do not expect any answer now, but hopefully, when he is arrested, we’ll find out.