Okay so today I opened up the editor, and a quick browse through the character resources found that the game comes stock with art assets for Malcolm.
If you look through <UT3 install directory>\UTGame\CookedPC\Characters, he's in the package called CH_Immortals.
Now I don't know the first thing about adding custom characters for UT3, so I couldn't tell you how complete these files are, and it would take me forever to try and learn how to fully implement Malcolm in to the game. But for anyone with a little skill, it should be a piece of cake to determine whether or not a playable Malcolm would be a simple job.
So who's up for it?