I wouldn't have thought so it's her responsibility if she has informed Ofsted and the local council. Do they both know about his other job? If not then I would definitely inform them about that as well as there may be things to do with safeguarding vulnerable adults that would be applicable in this case. But otherwise if it's Ofsted or local council that have advised that she can not do this then I guess her hands are tied.
I suppose an annoymimus call could be made tipping them off but that's a really rather obvious thing to do if she's been told not to and could end up getting her in trouble. Plus, looking at porn doesn't necessarily make the fella a risk, just a bit stupid for doing it at work and getting caught!