I may be wrong but I thought the guy who’s house where it took place, did inform the police, or at least involve a lawyer (probably to protect himself) However, I think after discussions between Celtic and the boys parents no formal changes were made. I’m guessing that rendered the police powerless since they can only investigate if someone states a crime has been committed. I presume you would need the victim to actually lay charges and the people involved to cooperate with them otherwise it’s all allegations from the police’s standpoint
I think the key thing in that incident is who the guy in charge of the tour tried to contact in Glasgow. He went straight to the top of Celtic FC for advice on the situation, not some separate entity