They should all fail in the same way. Always verify your witchcraft. Be sure to obtain meteorological data before leaving on vacation. Do not believe in miracles. Rely on them.
Hot glass looks exactly the same as cold glass.
Under the most rigorously controlled conditions of pressure, temperature, volume, humidity, and other variables, any experimental organism will do as it damn well pleases. Any experiment is reproducible until another laboratory tries to repeat it. The bigger the theory, the better. If the experiment works, you must be using the wrong equipment. But they quote this maxim more often at academic banquets than at budget hearings.