On the first level of the Guarded Compound, there's a trap that summons a demon and some other shit. This is not only heavily gay, since the demon just attacks the stuff it was summoned with, ignoring you and generally looking stupid, but is also a last-minute Bioware hack.
What was MEANT to happen, it appears, is that Ketta, the thief on the upper level, would backstab the party. This is indicated by the naming of the trigger region and associated script. I certainly think this'd be vastly more interesting than a load of random shit being summoned that doesn't even work properly. (It would eliminate the combat from the first level, however, so I'd suggest having some arbitrary shit summoned after Ketta runs off anyway.)