Griphook made a deal to acquire Gryffindor's sword from Harry but he eventually just took it from him while breaking into Gringotts. But, later when Neville pulled out Gryffindor's sword from the sorting hat (to kill Nagini), I believe it vanished from the vault of Griphook and didn't return.
While wizards don't agree with the goblins' way of treating wealth (goblins believe that a goblin-made object should be returned to the maker once the owner dies, instead of passing it down to generations), Griphook did have rights to the sword, via Harry (who was given the sword by Dumbledore through his [Dumbledore's] will).
Can Griphook plea in court to have Gryffindor's magic removed from the sword (whether it can be removed or not is another issue)?