There is no question a hunter is allowed to erect a tree stand on Crown land, the burning question is for how LONG?
Your take appears to be it stays until the end of the hunting season and as I pointed out there are many seasons you can run into back to back, starting with a Spring bear hunt and ending with a late season Moose hunt.
The problem is that some folk's leave their stand on purpose year after year in order to have EXCLUSIVE POSSESSION of an area of land to hunt on year after year to the exclusion of other hunters.
If you have built a permanent stand made of wood or what ever that cannot be easily removed IMHO its open to be used and its there against the spirit of the law.
If its a steel ladder stand affixed to a tree and easily removable then you would have to move off it if an owner arrived.
But that stand must be removed.
"Hunters must remove any temporary structures including tree stands placed on Crown land."
https://news.ontario.ca/en/backgroun...hunting-season