Presqu'ile Provincial Park which show a very similar deformity.
A sign near this tree explains that something damaged the central growing stem, or leader, in the case of the cedars as much as a hundred years ago. The tree's response was for one of the side shoots to take over as the leader, but it took some time for it to bend itself back upright, forming what is locally, and aptly called a 'saddle' - so the tree are known in Ontario as 'horse trees'. In the Presqu'ile Provincial Park a number of cedars show the same feature, so the damage may have been caused by a late spring frost, but other causes can be damage by insects or deer.
Many thanks to Bruce for the pictures.