As architect I don't understand how you can blame OVH here.
Local fire code is within the city council, which uses the local fire department, and then with the maintainer.
Without proper planning and fire code measures you won't get a permit.
How did the constructor got a permit at all? This is a wooden building for F 60?? This must be F90 for starters. Then the electrical planning: How did they get a permit at all?
OVH was only a renter. First I would blame local fire department for not enforcing their fire codes.
You don't rent a log house to operate a glass manufacture inside! Each construction have limits of usage, quality or quantity wise, you know that.
Those put their operation into a place must ascertein that the location can withstand the operations and its risks. Even renting a flat put limits on your activity in the contract, what you can or cannot do there.
If they requested the proper fire rating and safety measures then it is not their mistake being deceived. Otherwise it is.
It could be that only risk to life, limb and neighbouring properties was evaluated and (probably correctly) concluded that the combination of low-occupation, trained staff and sufficient escape routes meant that the risk was minimal.
If someone wants to burn down their own property, why not let them? That's up to the business and their insurance to judge.
OVH was only a renter. First I would blame local fire department for not enforcing their fire codes.