True, but part may be false.
Many species of petrel can indeed regurgitate their stomachs as a defense mechanism. Snow petrels and other petrels will also shoot yellow, waxy, fishy oil from their stomachs at creatures and people who intrude on their nests. However, they shoot this out of their mouths, not their noses. I didn’t find anything about this jet of oil knocking anyone down, but the smell of the oil (which is water-resistant) can stay for months or even years.