Aurel Littmann asked:
why is there a difference between how much the veshet vs the koneh is pogum before the animal becomes treif?
The Kollel replies:
Since the food passes through the Veshet, even a very small hole (that pierces the two layers of membrane) will make the animal Treif because the food that it eats will exit through the hole and entire the body and harm the animal.
In contrast, only air passes through the Kaneh, and if air escapes through a small hole and enters the body it will not harm the animal. Thus, the animal only becomes Treif when there is a tear through the majority of the Kaneh, in which case the air can no longer reach the lungs.
M. Kornfeld