The effect is caused by a number of objects or events, of which the cause identified is only a part (a variation of this is the feedback loop where the effect is itself a part of the cause).
- The accident was caused by the poor location of the bush.
(True, but it wouldn't have occurred had the driver not been drunk and the pedestrian not been jaywalking.)
- The Challenger explosion was caused by the cold weather.
(True, however, it would not have occurred had the O-rings been properly constructed.)
- People are in fear because of increased crime.
(True, but this has lead people to break the law as a consequence of their fear, which increases crime even more.)
Proof: Show that all of the causes, and not just the one mentioned, are required to produce the effect.