Just from reading the cbs8 story, the case does seem weak. The real investigation should be focused on why a small fire was allowed to grow and completely destroy a billion dollar plus warship. Nothing that floats is completely invulnerable but warships are supposed to survive after taking a good amount of actual combat damage. If a zippo and a bucket of accelerant (?) will take out an amphibious assault ship, how will it fare if, say, it takes a couple of hits from Chinese missiles and shells? Even small ones?
Yeah, that was a weak case, all right. And the fact that they were pursuing another suspect with equal MMO, then left off him, even with some compelling evidence? Not a good look at all.
As for the ship not surviving the fire... a ship undergoing reconstruction at a dock is a FAR different thing than a ship at sea, if for no other reason than its personnel, who are trained to handle fires, battle damage, etc., aren't there to do anything about it. At dock side the people who are assigned to protect it against fire are probably general firefighters, not really trained in what it takes to fight fires aboard a ship, especially once that's undergoing extensive rehabilitation and is likely packed with flammable materials not related to its role as a fighting ship.
From a few other articles I've read about this, it would seem that no one wanted to take authority (feeling that they didn't have the authority to do so) to lead the fire response. What that tells me is that, at least ashore and at port, the Navy doesn't value initiatitive, it focuses on rote, formualic adherence to Naval command structure even in the face of a catastrophe.