Upon decompiling t0a0, I got a lot of invalid brushes etc, but that's probably just the decompiler.
?The holographic assistant monster in the first room (Gina) is referred to as "Intromona". I originally thought it was a character called Mona, but "Intromona" could mean "Intro Monster A". Revealing there was perhaps another intro monster?
?Missing textures: The origin brush on a rotating door read as... e1u1origin - perhaps the hazard course was made when they were using older wads, like in the beta... Could e1u1 be the name of the old training room? I saw a pic of it somewhere... But it's a generic origin brush, so I dunno.
That's all i've tried so far. I don't plan on uploading the decompiled files since I forsee copyright issues. Instead, use
http://www.slackiller.com/hlprograms.htm
P.S. I'm not gonna even try and compile it...