My comment is more of a generalized observation. Your response seems to confirm it. Who makes the call on "shared" responsibility? I also guessing there is some sort of arbitration clause. (found it: https://aws.amazon.com/agreement/)

I'm not saying any of this is necessarily wrong, just not what people often expect when they dump, to them, a significant amount of money into something. Many midsize and larger companies like to "big dog" their vendors. They are not accustomed to the cog in a machine feel that most of us tolerate daily.