The Web of Evil

I'm really not very good at this sort of thing, but isn't it implying that A is caught by the legislation if, and only if, it can reasonably be regarded that he has violated person B's dignity with regard to both a) and b). In other words, B's perception alone won't do it and "all the other circumstances" alone won't do it either. I am a little baffled as to what these circumstances could be, but could it just be a catch-all for stuff other people might report, outside of B's perception, to imply that A has committed an offence?

In summary. only if evidence of both a) and b) is found to be present can A be convicted of the offence. Can this be right?