Is your manager going to disable your body? How is this even remotely close to a manager being able to fire you for whatever? You're just ignoring the whole "at-will".
I'm not talking about a "sword" of any possible negative thing happening to you. Why not bring up asteroids? Or another plague? Or just suddenly a REAL sword beheads me? THe "sword" is solely the at-will. Learn how metaphors work.