Station Park | 18, 28, 36, 40, 50 fl | U/C

[Camper]

I can 99% guarantee your floor height change from 11' to 9' is not a typo or miscommunication and is directly related to schedule and cost.  To change formwork is expensive and time consuming for 1 or 2 floors and this is probably either the formwork company offering a credit to the GC to keep floor levels at 9' or possibly the GC doing it to meet schedule and get occupancy dates.
The fact that they're telling you its just a miscommunication (and you have no way of proving otherwise ) is definitely crappy on their part.

Its the other way around. No chance that the drawings show 11' and the formworker/GC is trying to "save time/money" to form 9'. That just doesnt happen. Plus they have Verdi on this job who would form 20ft without question.

Sales/marketing gets details about floors from construction. Someone made a mistake or didnt properly check the drawings. It could have been clearly shown or there could have been a transfer slab that would not be picked up by some office staff at the sales/marketing stage.

Actually it happens quite often that subtrades propose changes in exchange for credit.  Especially the big structural trades. Obviously the forming company could do whatever is drawn but there is definitely time and financial savings by keeping as many floors typical as possible.  Plus those 4th floor podium suites wont sell for big bucks like the penthouse units so the 11' ceilings could have been scrapped before construction began and the change failed to make it to the marketing team. 
Either way even if I'm wrong or you know something I don't,  it sucks for the person buying a unit that thought they were getting high ceilings.