Could they have done better? Sure. Hindsight is 20/20.

Would it have been a reasonable assumption? No. As pointed out in the parent, every bank pretty much works like this, they're all liable to go under in the presence of a big enough run.

Also if it must have been so obvious to them, it probably should have been obvious to the regulatory agencies in charge of monitoring banks and avoiding exactly these situations, as well as the Fed who set the policies leading to this in the first place.

It just wasn't part of anyone's threat model.