If the airline doesn't comply afterward, it would be on them.
But they didn't issue a recall, so they wouldn't have to pay for the fix, an over 200 people paid the price instead.
At least, that's how I read the blame distribution.
This premise implies that if you could prevent one plane crash for $10 trillion dollars then you should do it, but then ordinary people wouldn't be able to afford air travel. In reality they do have to consider the cost and then do the things that are justified based on the cost and the risk. Which means that high regulatory costs compromise safety because the more it costs to make a change that improves safety, the fewer of those changes can be implemented for an amount of money that can be justified by the risk.
Means nobody can fly. The FAA does understand this, but the mass media does not.
A 100% safe airplane won't move an inch, let alone fly at 30,000 feet.