DY never said the room number; it was only shown on the graphic. IMO, DY knew exactly what she meant, but Dr. P's staff screwed up the graphic big time. We already know they got the room number wrong. IMO, his staff got the stairwell wrong as well.
On Dr. Phil, DY says TH claimed she waved to Ky from the top of the stairs from that side entrance, East end of the school. The key word here is side entrance.
http://www.drphil.com/shows/show/2069/ (1st video clip of interview). Watch DYs hands as she describes the position of the stairwell.
IMO, the Dr. P staff did not realize the side entrance to which DY referred is actually the front stairwell/main entry way. The stairway marked on the Dr. P graphic is the on the END of the school, not the side. (The actual front/side entry doesnt even clearly show up as a stairwell on the TV map.)
During the Dr. P interview, DY would not have been in a position to easily see a program monitor displaying the graphic, so she would not have been aware they were broadcasting misinformation. (Trust me on this one; my background is broadcasting.)
Plus, it makes no sense that TH would exit through the throngs of kids getting off the bus and entering the school from that east end door. (IF, of course, she was still in the school at 8:35 when the buses arrived and the first bell rang.)
ALSO
Does anyone have copies (not links) of some of the original reporting? IIRC, THs mom (I think) said something about TH going up one stairwell and KY going up another stairwell
TH waited until Ky appeared at the top of the stairs, near his classroom, then waved. I could swear thats one of the early iterations, but the news reports have been updated and rewritten so many times, that version of events no longer exists. Or else Im making it up. Also possible! Although not intentional.