If you get a piece of loot, then yes it is yours. I understand exactly what you are saying, but it’s already been covered. Ion clearly stated that the instances that you get something you don’t need but can’t trade it is simply bad luck. It’s not a big enough issue to even look into.
That is more an issue with rng. That could be looked into for sure, like adding a currency and raid gear vendors. Adding ML is not the answer. Still the main reason for PL isn’t to keep you from giving gear away, it’s to make sure that everyone is getting gear.