In the Disney movie 'Moana', Tala who is a grandmother of Moana said "Whatever just happened… blame it on the pig."
I've googled and found some headlines like 'Flu? Don't blame the pig', so guessed 'Blame the pig' means blaming someone who is innocent. And the sentence in the movie was a kind of game of words since there is a pig character who is a friend of Moana.
Best Answer
Pua, the pig, is one of Moana's side-kicks, with comedic behavior you might find in a puppy-dog.
When Tala sees the damage to the boat, the boat that Moana was not supposed to take beyond the reef, Tala advises Moana to blame the pet pig, so that Moana will not get in trouble for disobeying and for ruining the boat.
She says, "Whatever happened..." (meaning that she doesn't want an explanation) that the best thing for Moana to do would be to, "blame the pig".
http://disney.wikia.com/wiki/Pua_(Moana)