I actually think e has a pretty good case against the City, the Inspector should have already been BOOKED AND CHARGED for this Fire.
It is the Responsibility of the Fire Inspector to assure the public of the buildings safety, they never did any such inspection, instead they just kept ignoring the LAW.
See Flint Michigan Prosecutions over Poison Water
No Fire Inspector will be charged because no fire inspector ever entered the building for an inspection. Fire inspectors in big cities don't go around randomly inspecting buildings. Inspections are typically prioritized and assigned by a Fire Marshal or a Chief in charge of the fire prevention bureau. A list is given to the fire inspector, and he just inspects what's on the list (or if he is sent out to a particular building in response to a specific complaint).
In this case, Oakland doesn't even have a fire marshal, the Chief of the department taking that role to herself. If there's any scrutiny due the fire department in this case, it should be placed on the Chief, or her higher-ups in the City, if they mandated her organizing her department in this way.
Having said that, I place the blame squarely on the building owner. Whether he got an inspection or not, he knew he was occupying the building for illegal use and he is the one who allowed the building to devolve into a firetrap.