I was under the impression he had a pretty large creative hand in the development of WC Privateer, which I LOVED in the early 90's, but maybe not?
He pitched the idea to the owners of Origin... as a pretty fresh 19 year old. They hired him and allowed him a Co producers credit... but they put the experienced Warren Spector on it. Which is why WC has all the branching story line stuff... which is a huge hallmark of a Spector game. Its why System Shock and even DeusEx feel almost a bit more like the early WC games then any of the later freelancer games.
Origin gave Roberts more control of the later WC games... but he almost put them out of business with every single one as he went WAY over budget. I can't remember which think it was WC4 that only shipped because Origins owners basically told Roberts in front of his team that if they didn't ship it by the end of the week all their pay cheques would probably bounce.
Roberts should be a known quantity to everyone at this point.... but like any good con man he has done a great job of Catching and destroying every negative story/interview possible over the years. There used to be interviews with the Origin founders where they said things like ya we like the kid but we would still be in business if we never met him. Spector was on record (good luck finding it now) as saying Roberts was a tool... I read an interview years back where he related a story about Ken Demarest was showing the Origin guys one of the first Fully 3D engines he was working on, and Roberts was the one guy that just didn't get it. (as far as I know Demarest was the first person to ever code texture mapping) Ken created Bioforge at Origin.
Anyway I'll digress... I know my Roberts hate can be a bit strong. lol