The glowing means he was using a high gl_modulate value. This is more or less a built-in Q2 cheat that allows you to see in the dark. It's been removed from the standalone version. There are some other settings for this, but I can't remember what they are off hand as it was a long time ago they were implemented. One of them forces a lower gl_modulate, and the other makes players glow, tints their screen yellow, and sends messages telling them to turn their gl_modulate down (basically levels the playing field - if they can see you in the dark, you can see them in the dark).
Glowing aside, though, there were several suspicious behaviors, such as shooting players right when they came through an opening, or running to a different location to cut them off. Also, either he was stupid or he had some kind of auto-fire on because he was shooting at teammates, too. Then there was the failed nocheat thing...
It would be nice if server admins would set sv_minclientbuild -- that at least cuts out the most basic Q2 cheats right off the bat, and the updated server will help detect/ban most of the rest.
