We know that Luu was misunderstanding at least some things, since he gave an inaccurate description of what was happening. Given that context, I find it more plausible that he was also misunderstanding other things, than that the thing was broken for him despite other people seeing it working. Even if you weigh the likelihood differently from me, you must admit that that's a possibility, so concluding that it was broken because Luu thought it was broken is at a minimum premature.

Given the other comments talking about problems here, we don't know for sure if it was inaccurate. But even if it was, "plausible" that he was misunderstanding other things is a hell of a lot weaker than the way your comment above treated it as the truth of the matter.

Overall I think it's pretty unlikely that it wasn't broken.