I just listened to the police scanner audio as this was happening. They made several references to shooters on the 29th and 32nd floors. I am not much of a tin hat guy but something does seem to be off here.
That's close enough to be one set of observers going by actual floor number that you'd see on the elevator and floor signage, versus other observers counting up the floors from across the street. The latter not taking account of, at least accurately, how many mezzanine floors and the like, nor where the 2nd floor starts, when the count.