Examples

Let's look a few examples of uncommon examples:

'An elephant is a mammal, because it has tusk'

Tusk is present in no other mammals. Nor is it present in non-mammals. Thus the reason tusk, is  present, neither in similar instances, nor in contradictory instances. Hence this comes under uncommon straying.

'Humans can create things, because they have the sixth sense'

Do you think this is a valid argument? Though it may seem so, it suffers from uncommon straying. Sixth sense is unique to humans (atleast, we believe so). Hence the reason is  present neither in similar instances (i.e. those which can create things), nor in contradictory instances (i.e., those which can't create things).