I started the "disagree" conversation. I intend this to mean the computer disagrees. The consensus is most aircraft computer systems these days are very very smart, and have a good grasp of what the aircraft is doing, what it should be doing and what constitutes smart actions and what is not. So if a pilot tries to shut down an engine, and the computer thinks that's not a great idea (Kegworth, Jeju, Air India, no doubt others) then the computer says "disagree" and the pilots are required to then press a 2nd button located someplace else. To my mind this second button would have the fidelity of the current "fuel off" button, i.e. it's a straight cut-off, no ifs or buts.