You are either saying that the DM, who knew that the gauntlets were gauntlets of ogre power and not simply replacement gauntlets for those missing from the adamantine armor, didn't think of those items as being two separate items (magic gauntlets and magic armor), or you are absolutely wrong that any clarification beyond "the armor" was actually necessary.
I think there are plenty of players around who don't care very much about bundling/unbundling and the minutiae of buying and selling, but do care about having magic items for their PCs. I'd put myself in that category!
Yet, at my table, everyone knows that "the elf" doesn't mean "the drow". This is an illustration of the point that "defaults", or decontextualised dictionary definitions, aren't generally relevant to interpretation except as a rough starting point. Mutually understood intentions to refer to one thing rather than another, based on mutually understood recognition of what is or isn't salient in the context, are far more important.
This is just restating your claim, without answering my question.
The GM knew the player didn't want to sell them! The GM knew the players would be disappointed when he told them that the ranger had sold them. But because the player didn't use the GM's preferred from of words to express his intentions, the GM has held him to have declared an action that he did not want to or intend to declare. (Once again, contrast a player who says "I leave my backpack behind" forgetting that something valuable is in the backpack.)
