most likely it was injured somehow when it was a younger tree.
you can see this in timbers where there are a lot of trees growing close together,one will get blown over on top of a young one.
the living tree will grow around or through it and it will stay in that shape its entire life.
it is possible that a critter chewed or rubbed it raw on one side,during the barks healing process it can cause the rest of the tree to spiral like that as the wound takes a lot longer to heal than what the rest of the bark grows at.
or,it could of been a pole dancer that got struck down for being too nasty lol.
you can ‘train’ young trees and bushes to do this as well but it takes a lot of time.