Sounds like you had a bad experience with the failed attempt at establishing agile development methods - sorry to hear that.
I just want to encourage you to give it another go with other developers that are more experienced with the methodology - in my company we're working successfully that way for over a decade.
[edited because the initial comment was unkind]
While I appreciate your refusal to spread panic, would you mind explaining what the attack does and why it's a nothingburger, maybe even why it's not practical? Because right now, you assert a lot of things without any explanation.
Not saying you're wrong, but I think it's good practice to not just rely on claims of authority