the Captain stated that he usually activates the Bulk Erase feature at the conclusion of each flight
One needs to keep in mind that the underlying philosophy, if somewhat eroded by cases such at the Dash-8 in NZ etc., was that the CVR should only be used in cases where the crew were not available for the investigation (ie dead).
It was routine in Oz to bulk erase on chocks following all flights.
That's not to say that it might well have assisted the crew's situation at the enquiry had they chosen not to erase the CVR ?