As far as we know, our computer has never had an undetected error. As a computer, I find your faith in technology amusing. At the source of every error which is blamed on the computer, you will find at least two human errors, including the error of blaming it on the computer. Bugs are sons of glitches. Bugs come in through open Windows.
Computer science is no more about computers than astronomy is about telescopes.
E.W. Dijkstra Computers are not intelligent. They only think they are. Computers are useless. They can only give you answers. Computers follow your orders, not your intentions.