One thing that seems to be developing is a split between the FAA and the NTSB, the Feds siding with Boeing, and the NTSB seeming to be coming to much more cautious views. I somehow get the impression that this also represents a split between the manufacturer and the purchasers/operators, along similar lines.
It really is surprising that Boeing still doesn't know the root cause, like why the battery shorted in the first place, and why the multiple safety systems then didn't work, which is what the NTSB seem to be gunning for, not so much the FAA. Has McNerney really outsourced everyone who might be expert in this ? De Havilland got to the root cause of the initially inexplicable Comet metal fatigue accidents when all the evidence was laying at the bottom of the Mediterranean. Boeing are fortunate that is not at all the case here.