I wouldn't put it past them. Breitbart recently got caught redubbing a black news reporter to make it look like he said something racist.
No media should be trusted. Not mainstream media. And particularly not internet media composed by nothing more than glorified bloggers.
That Breitbart would do something like you say (the redub), would not surprise me in the slightest. But on the flipside, I would not be surprised in the slightest to see it coming from the other side either.
Russia Today's current marketing slogan is "Question More" and people blindly post their stuff like the exact same slogan doesn't apply to their content also.
Personally I prefer the slogan of the X-Files. Trust no one.