‘ey raiding Bears, got a question for you

Is Blackstone Ring part of our prebis? I just had some loot drama with a 51 Rogue after I won the roll for it and wouldn’t sell it to him (which I’m pretty sure you can’t do with BoP 5man loot). As my main is a raid tank with +hit gear, Blackstone Ring was part of his prebis, but my area of expertise is not with Bears. Was I right to roll need on the item, or should I have just let the Rogue have it?