A shortening of the Hawaiian proverb “ahu ka pala naio.” (Actually an incorrect proverb) “ahu ka paila naio” means a heaping pile of larvae (usually fly). Basically a heaping pile of shit, or bullshit. Paila naio can be used in expressing disbelief, but depending on how strongly you feel, you can use the whole quote.
I call paila naio, she didn’t say that to him