apparently his name is andrew january. Its says it on his hotmail address. On the bottom on the page he says he was the former lead coder on the HL:bumper cars mod. I figured he must be [IRC] then. I checked the website and found his e-mail. I could very well be wrong. they might have changed coders for the final version.
http://www.planethalflife.com/bumpercars/about.asp