Probably similar to the experiences of some Tesla drivers.
An automation failure would throw the pilot back to basic stick and rudder skills, potentially leading to an accident if he or she wasn't prepared for that. Aviation safety professionals identify such unexpected scenarios as "startle."
That's the trouble with automated systems, they are overconfident and won't tell you there is a problem until its too late. True AI when it finally arrives will be just as bad except it will put up a message saying "I told you, you went weren't as good as me. Look, you crashed, you dumb meatsack"