You don't know what you're posting about.
As I said, Von Essen looked "lost" in the lobby of the WTC, just walking around, not taking command, the same when walking with the mayor, Von Essen was not "monitoring" radio traffic, just walking again looking more "lost" than earlier. (all shown in the movie made 911.)
As for the WTC roof doors being locked, the roofs were suppossed to be a safety exit for escape, but the doors were locked in a jurisdictional dispute between the police who had helicopters for resuce and the fire department high officials.
I am a former firefighter/paramedic. I think it'd be impossible to use helicopters for roof rescues in that situation. You had a broadcast mast on the one tower and commercial 2-way antennas on the other one... air turbulance due to the heat and smoke so thick you couldn't see where you were going. Did you see any rescue choppers around those towers in the news footage?