Hocking made his name in the industry at Ubisoft as the creative director on Far Cry 2 and Splinter Cell: Chaos Theory. He joined LucasArts in 2010 to work on "unannounced projects," and left before the company folded to join Valve in July of 2012. While the project(s) he was working on at Valve was never announced, his name popped up on a list linked to Left 4 Dead 3 via Valve's Jira database late last year.
http://www.ign.com/articles/2014/01/06/clint-hocking-leaves-valve