If they fulfilled the requirements provided to them I don’t see how that could be the case. Even if they didn’t it was Boeing’s job to verify that.

It’s a bit like blaming low level construction workers for a bridge that collapsed (assuming they didn’t sabotage anything on purpose).

You should always question if the requirements you get make sense.

And? How would that help if they have no clue about how that specific system was supposed to work?

You find out. Doubly so if you're working on safety critical systems like an airplane