I think driftglass's point was that MSNBC is not the mirror-image of FoxNews. In my skimming of the Pew story you linked to, I didn't see anything about the lies that FoxNews spreads. Would those count as "facts" or "opinion" in Pew's methodology? I can't tell.
http://foxnewslies.net/?p=1
Cheers,
Scott.
(Who only watches 2 shows on MSNBC, and infrequently at that.)