Again, it doesn't come down to a single person. In a typical setup for a project like this - you have
X number of Developers - per platform (iOS, Android, Web, etc)
X Number of test esters (Sometime also per platform)
X number of BA's
X Number of QA's
X Number of Product Owners
Scrum master
Business people
etc etc..
Now, collectively they are all responsible for the product they put out. A developer will develop something accordingly to the spec they are given and no more. (Sometimes less) and its up to the testers, QA, BA, product owner, etc all to verify. - The product is tested at multiple levels. Right up to internal staff and even business people will test it before go-live.
Sometimes, the issue can be poor direction from Product Owner, who gets business requirements from the higher up that may be vague. Maybe timelines were too tight and shortcuts were taken (Seen that happen at a large tracking company) and the end result is ****.
It's multiple people, in multiple roles to get something like this out the door.
I get where you're coming from; but in my experience (Of 8 yrs as a developer for big companies) AA or BEE isn't the issue either - but you're free to make your own assumptions.