In a lot of ways it’s like investigations into airplane crashes.
The good news is that the grid operators have a good idea of what the problem was/is and it's well understood how to fix it. The downside is that it will require quite a bit of both time and money to reinforce the grid infrastructure.
Every major grid operator around the world is going to study this and make improvements to make sure this doesn’t happen on their grid.
If over here a lady buys a hot coffee in a McDrive, drives away, spills the hot coffee on their legs and makes a car accident due to this ... she won't be able to sue the McDrive. There's no fine-print or "Coffee is hot, you dumb person" writing needed anywhere. She could be lucky if she doesn't get fined for endangering others by her stupid actions.
So, if we have a power outage here, the courts don't suddenly get busy. Because there simply no one is suing.
Fun fact: despite this bad power outage, the power grid systems in Europe are still better (even way better) than in the US. There is a comparable statistics measure called "SAIDI" --- system average interuption duration index. And duration wise, per custom and year, the US power grids are worse than over here than in most of West Europe: (US SAIDI 2020: 1.3 hours, German SAIDI 2020: 0.3 hours). That's a factor of more than 4 on the worse-iness of US power grid!
That could be an indicator that suing at the tiniest chance isn't helpful macro-ecnomical. Or that a general suing culture (with legalese trying to protect one from the economic risks) aren't actually helping improving things in the general sense, although they reduce the risk of getting bankrupt. But society-wise, a sue culture is most probably a negative: you spend energy/time/money on things that aren't necessary in saner law systems.
Spotted the US-american
We had a problem some time ago with a major power outage due to operator negligence. When it came to assigning blame it turned out the corporate structure was such that it was impossible to sue the operator. Since it was in effect publicly-owned, the public would have been suing itself.