In British law there is no such privilege guaranteed by law Fisherman. For any religion. So I'm sure you can appreciate that when you ask for my personal views they will be shaped by that common law. There'll naturally be a huge gulf in personal opinions between us just from that. Personally, I think JWs should have equal or equivalent rights to any other religion as best a court can make any relevant laws fit.
I think how you describe a scenario would fit within most exemptions to mandated reporting, however the investigative nature of a judicial committee would need to be stopped too. That's a real barrier for JWs in how they try to run a quasi-legal system, and it is always going to rub against secular law in some way when it comes to crime. They recognise it themselves with their instructions to elders to hide from secular authorities the fact that they're doing an investigation. Even outside child abuse, having someone playing private investigator whilst a criminal investigation is in process could prove very harmful to justice.
In any case, as indicated by the Anglican church's suggested revisions to the code of conduct for their own priests, there are troubling moral aspects even to that priest/penitent/God aspect. How religions solve that seem like something which they need to figure out lest secular society ultimately decide a solution should be imposed. Which is the solution which the WBTS seemed to be begging ARC to recommend, which was very confusing given how they fight so hard not to report on 'religious freedom' grounds.