When you pick up a rune with someone else his bottle you cant use the Rune in it.
It wil say Owner: Player(Bottleowner). And get unusable.
And when u pick up a rune you can stil drop it / sell it.
As in dota1 everybody can use a rune if he picks up the rune with someone else his bottle,
but cant drop it/sell it until used as it would get abused.