I have flown with many check airmen in my major airline that have while they are flying and I, as the FO, have to coach him through how to land manually when he screwed up all the automation. Another time I was doing a departure out of San Jose, Costa Rica when I was flying that I just ignored all his inputs and made a climbing right turn while he had me programed for a descending left turn. Automation is great when it works but don't blindly fly the FD when you know it is wrong. Another time out of LAX in a 767 he stayed in TO mode and busted the 2500 ft level off by 300 ft and was 300 kts when I said to reduce the throttle, lower the nose and all is well. Automation can help you or kill you, depending how far you let it go. Check Airmen don't fly the line much so get behind things easily. You can make any airliner made by Boeing into a 727 with two clicks.