Writer Jay Pinkerton left Valve last June but a few hours ago Valve's people page was updated with Jay Pinkerton with the following description:
Looks like he may have returned to Valve after about a year.
Jay Pinkerton is a comedy writer who fell into game writing completely accidentally fifteen years ago and has been waiting for somebody to notice ever since. Prior to joining Valve, Jay ping-ponged around the industry working with very nice people on games that were worked very hard on and then shelved forever. Prior to that he was an editor at the then-resurrected Cracked.com, and helped get that online. Prior to that he was Managing Editor of the National Lampoon. Prior to that he was mostly freelance writing, which is a professional way of saying he starved for a living. Prior to that he was a child, then a baby, and then hadn't existed yet. That pretty much catches you up.
Looks like he may have returned to Valve after about a year.