Then when your cry is genuine no-one will believe you. If there was one man in the Village to prove to be a stumbling block in the execution of No.2, then that man would surely prove to be No.6. So someone had to have No.6 discredited, so that he was not to be believed, not even when he cries wolf to the intended victim.
But then why should No.6 care what happens to No.2, well of course he doesn't. But he does care what happens to the innocent people, in fact No.6 seems to have gained a social conscience all of a sudden. Which to me seems to be completely out of character, as he's never bothered about the innocent people of the Village. Certainly he has no time for them in the next episode, as No.6 has reverted back to the "lone wolf," and the citizens have no time for No.6, short memories that they have. Indeed they are quick to turn on No.6, as he is posted as being "Unmutual!" But then of course the good citizens of the Village would have had no indication of what No.6 had done for them in the previous episode Its Your Funeral, as they would not be aware at the time, nor be told afterwards. So it would seem that the equilibrium, the status-quo of the village, has been maintained throughout.