Halon dumps: a data point

I was in a 25x25' computer room, alarm sounded, we scuttled out, then looking in the window it seemed like nothing happened. Stuck our noses in, seemed ok, so we went back to work. We were checking some on board diagnostics, and the lady I was working with was reading some status lights for me to check in a manual and proceed on a test terminal. As soon as she started reading off the numbers we knew something had happened as her voice dropped an octave or two. Kind of the opposite of helium. We didn't stay in the room, but noticed no ill effects, and returned a few minutes later after the room was refreshed. My understanding is that the only problem with halon is that it can displace the oxygen, not that it has some direct toxic effect. OTOH lets not repeat the last thread.