It's perfectly acceptable to violate a contract. It doesn't matter you're not a fan of this. As long as you follow through with the terms of violating it.
> Breach of contract is not a crime or even a tort. Punitive damages are generally not an available remedy. The only remedies are to make the non-breaching party whole. The main theory behind this rule is that the law should not punish economically efficient breach.
The contract was not in the article but we can assume that it would be whatever financial compensation would be to make them whole. That's something they offered but the other party kept making threats that they would be criminally charged, even though the article states it was within their rights to not sell the goat.
IANAL but I can't imagine what permitted the police to be involved.