@Haben Hagose, I don’t know anything about that specific story, but I know a lot of extra folk-law often gets added onto the lives of saints like St. Patrick, so he undoubtedly features in a lot of fictional stories.

But as well as that there are likely a lot of true stories about him that aren’t necessarily included in each article about him. He was a wonder-worker who travelled to many places in Ireland over a period of decades; every area he travelled to probably has some stories about what he did when he visited the area.