This is a tricky one but a great discussion. Tell me if I'm seeing this correctly...
Theoretically,
1) if fish given to a non-licence holder remain as "possession" to the licence holder, and,
2) if the same fish cannot be counted toward two separate possession limits,
3) there is an open agreement to where the fish came from.
So Angler A catches his limit and Angler B catches his limit. No issues. Then they both give their fish to Norman No Licence. At what point do two limits of legally caught fish become illegal? Can Norman keep these fish as long as Angler A and B acknowledge the fishes origin if required, AND, neither Angler A or B have enough fish in their personal possession that would put them over their limit INCLUDING Norman's fish??
Well, this would be hard to nail down but that's not the discussion. And since it would be very difficult for law enforcement to enforce, they generally make it easy on themselves and simply state, nobody can have more than a possession limit. And to me, this makes sense. Being a non licence holder is not really an excuse for not knowing the law. We don't forgive poachers with no licence, newly landed immigrants, people from Ottawa, lol kidding.
Maybe I'm seeing this wrong but at the end of the day, the MNR would not like having an escape clause that can put a pile of fish in one place on a technicality.