Well, yeah, there are a lot of such design flaws in important systems (like commercial aviation) that are either a shortcut (profit cost-cutting or prohibitive costs) or not having enough data on the possibility of occurrence so you can't make an informed decision (and you just can't have it all otherwise nothing ever gets built).

What you described seems like the latter since they knew about it & deliberately decided it doesn't need fixing/changing, but was fixed later when they presumably determined that it made the accident worse. Idk anything about it tho.