I assume you can still do checks if you are on duty at the time of the incident? Or has data protection gone really mad?
It's probably not actually data protection, but more the force doing a bit of traditional arse covering. I can't really see a reason why Vike couldn't PNC and give words of advice himself - if he was on a police cycle, he could, if he was in a police car he could! He's using the systems in an open, honest and legal way, in course with his duties.
That said, if there's an intention of any sort of court or formal proceeding (I.e. other Han 'words of advice') then I fully agree that Vike shouldn't PNC and investigate himself, as he can't be seen to be approaching it from a neutral standpoint, which we must. It would be similar to me being the investigating officer for an assault on me - it just wouldn't look good, and could give the defence an angle to go with in court.