A programmer is asked to write a program that will raise and lower a large X-ray device. He writes and tests his program. It successfully and accurately moves the device from the top of the support pole to the top of the table. The program is installed. Later an X-ray technician tells a patient to get off the table after an X-ray is taken. The technician then sets the height of the device to “table-top height.” The patient, however, does not hear the technician and is crushed under the weight of the machine. The Xray technician, we might say, should have been more careful.

But what about the programmer? Isn’t it part of the responsibility of a programmer to think of “worst case scenarios” and guard against them? Or is this just another instance of “user bewares”?