Ok, i got Your point.
But this situation was more complicated that this what can be found in some scources, including the one you mention.
On the auditorium, when suicide bombers were located, assault teams were shooting them in heads. More, there were some places where aerosol did not reach (couple of hostages tried to escape on their own)
But on the other places in the buliding (higher ones - narcotic was appiled only in lower ones) there was a series of heavy gunfights, even MGs and genade launchers were used.
There is a couple of others elements - like planning and executing entire operation almost without radio communictaions (all channels and frequencies were jammed to prevent remote detonation of explosives)
So form the tactical point of viev, it was one of the best HR operations.
Russians spent a lot of time, after crisises in Budionnovsk and Piervomaiskoie, preparing for such scenario.

Had there been field hospital deployed,and evacuation routes to other hospitals cleadred, there would be many less killed.