I think Roger Ailes made Sean Hannity denounce Cliven Bundy. Hannity didn't object when the "patriots" aimed guns at federal agents. Hannity only objected after Bundy's racist rant. Most people probably saw the short version of the rant that Media Matters and the NY Times publicized. Some of the right wing media later released a longer version. It included footage of what Bundy said before and after he told us what he knows about "the Negro", and he wondered if blacks were better off as slaves. Some right wingers tried to argue that the longer version shows Bundy isn't racist, and that the liberal media edited the video to be misleading. In fact, the long version does portray Bundy's racism as more of the result of ignorance, and less due to animosity, than it appears to be in the short version. But Klannity, of all people, didn't pick up that ball and run. Somebody ordered Hannity to not fight that battle. If you also consider how micromanaged Fox News talking points are, there is little room to doubt that Hannity was ordered to denounce Bundy, in no uncertain terms.
Another aspect of the right wing's reversal of their support for Bundy, is how could anybody have been surprised by Bundy's racism? Some right wingers even said that Bundy just wasn't media savvy enough to word his statements well. As if there was nothing wrong with what Bundy said, just how he said it. In an alternate reality where Bundy and his armed militia friends are heroes, and a POW and his family are villains, how can anyone not see that the irrational extreme knee jerk Obama derangement syndrome isn't based in racism? Who do they think they are trying to "take our country back" from? The politicians who supported Bundy, and then dumped him when Fox News told them to, know.
If Bundy hadn't made such a fool out of himself, the right wing would still publicly back him and his supporters. It wouldn't be hard to wiggle out of blame for the Las Vegas murders though. The white supremacist gun nut Bundy supporter killers of two law enforcement officials and a citizen who got in their way, would be denounced as a few bad apples. Two bad apples in with the bunch of good apple white supremacist gun nut Bundy supporters who pointed guns at law enforcement officials.