Several points there, PPY. Firstly memory is not unlimited in the system. I am 'OK' with coding, but your 'lay' line is all 'ANDS'. Now write in options for unreliable altitude, AoA, thrust and attitude and any combination of these, and you will 'hand control back to the startled pilot', no doubt, at some point - now even more 'startled' because he expects HAL to cope with most things.
Your last phrase is the only viable one, since it is the only one that will cope with actual computer failure/malfunction.
Way back we discussed the 'big red button' option, which I am in favour of, where when pressed it does exactly the S&L function, based on last know valid parameters, but only when a conscious call is made, and not when 'IT' decides.
We need some more discussion, here, guys and girls. Is this a way forward?