Is Brian Williams to Blame for Edited Zimmerman Call?

Since 2004 Brian Williams has been, the managing editor of NBC News. NBC flagrantly edited George Zimmerman's 911 call to police to appear to make him look vehemently racist. As this item suggests, like Dan Rather, should Williams get the boot? Admittedly this is probably not as controversial as a newsman forging documents to change the outcome of a presidential election, but it does show the same disregard for the facts in which many people will believe and form their opinions around.