Another miscommunication?

I think we've got one of those difference-of-culture misunderstandings going on: I had a look at the joists for the corridor above the bathroom yesterday evening [and again this morning, when I could stand on the concrete of the bathroom "floor"], and it looks as though they are NOT lower; in fact when the floorboards are eventually put on top of the particle board, the floor will be slightly higher than it was.

What we didn't expect [because it wasn't mentioned?] was that the floor in the two bedrooms above is going to be higher.

Now I'm worrying that by "lower" they meant "only slightly higher" than it is now but lower than it could have been/the bedrooms will be...

So we still have the same problem we discussed - a step up under a low beam; just what we were trying to avoid, and no better head height under either of the beams crossing the corridor. It seems an awful waste of an opportunity; by lowering the joists six inches we could have done away with a step up in the corridor, and made it much safer! There is sufficient headspace in the bathroom to do this, as the ceiling is going to be lower anyway to accommodate pipes/cables/VMC tubing.

It's taken the edge off my enthusiasm. And definitely put a damper on my spirits.