On the CVR discussion I don't think they could use it and not because of the 2 hour loop.
The lawyers know it was likely not recording at the time. However it is almost certain there was considerable discussion about the event when the flight eventually departed. And that is what they will say they are after.
They also know it will have been over-written.
But the "black boxes" are very powerful in the eyes of lay people. So it will be pretty easy to use this apparent "new development" to maintain public interest and cast suspicion.