I agree that what showed was his, i.e. Roberts, liberal thinking. However, I also believe that he was given a nudge/suggestion based on something the public is not to know. He should have been given more vetting but apparently the nomination by Bush was taken to mean a conservative was being offered.
I just don't recall him promising to be a "conservative" when he was being confirmed. I remember him likening himself to an umpire, calling balls and strikes. Of course, that kind of assurance is not too illuminating, but more importantly, that kind of assurance is intentionally not too illuminating.
Some umpires have large strike zones and some umpires have smaller, less liberal strike zones. Once the pitchers and batters get to know each umpire, they can adjust their game.
I guess it's about time we start adjusting to our new Chief Umpire. It seems he's a liberal.