Robert Cherone, 45, was killed at Palermo's Pizza West Milwaukee facility after being crushed by a robotic machine, prompting an OSHA investigation.

Inflexibility of these expert systems in applying rules, and the tunnel vision implied in their limited knowledge, that can result in poor conclusions. Expert systems couldn't reverse their logical conclusions if later given contradictory facts. For example, an expert system would conclude that Bill Smith has ten toes because Bill Smith is a person and all people have ten toes. However, it couldn't then deal with the fact that Bill Smith lost three toes in an industrial accident. A human, using "non-monotonic" reasoning, has no problem concluding Bill Smith has only seven toes.