Why should caution be used when identifying the Mojave rattlesnake based solely on its tail tip?

Answer

The tail tip is frequently uniformly colored, but this rule is not absolute

While the Mojave rattlesnake frequently has a uniformly colored tail tip, this rule is not absolute, meaning visual identification in the field should always be approached with caution.

Why should caution be used when identifying the Mojave rattlesnake based solely on its tail tip?
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