Ooh, nasty! I’m afraid I’ve never had a character holding the box arrested, but it does sound as though the functionality that’s meant to stop you stealing the box from Shadowheart is preventing you removing it from the chest.

Have you been to the goblin camp yet? I’m wondering if you haven’t and you go there without SH it might jump to you in the cutscene that happens first time you go.

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"