Not an Airbus pilot...
Are you saying that the autopilot can never be turned "off" on an Airbus?
You can never "disconnect" the A/P totally and fly it manually at any time?
I have to answer with a "yes, you still can, but ....".
If you "disconnect"the Autopilot, you still guide the Airbus via a Flight Control Computer, which in turn directs actuators and finally the aircraft (same goes with the Boeing FBW system).
The FCC has the famous "protections" built in who restrict the inputs to stay within the programmed envelope. To restrict and direct, the computer needs sensors and those sensors can fail or ice up or etc. etc. The "feeling" of the computer is therefore wrong, just as the resulting restrictions of the inputs will be wrong.
So in short: HAL is still fiddling with flight commands even with the AP OFF.
In an Airbus you would need to force the computer into the famous "Direct Law" to shut out the protections and have almost unrestricted control.
The whole problem is
"if", or "how" and "how user friendly" can this be done.
Or in other words: When the
hits the fan, does the average pilot have enough possibilities / skill / hard- or software to achieve this in survivable time.