I know a case where the captain passed out on final approach ,but it was the (training)FO leg and he landed safely ,he was trying to get the plane of the rwy by using the pedals - the plane was a 737 - still on landing "run" and stop on the taxiway when the capt. came around again. The company do not allow FO to taxi. The capt. passed out due to kidney stones (if you ever had that once you know how it can be so sudden and intense that you may pass out in pain).