If you haven't already seen it, I recommend to watch [Login to see the link].
I infer from it that, in addition to her musical gifts (one of the greatest British hit songwriters ever), Christine McVie also probably saved Stevie Nicks' life. It seems Buckingham & Nicks were always at each other's throats, even back from when they first joined the band in the '70's, and when Christine came back to the group following her decade+ absence, Buckingham was still a physical threat to Stevie. That's why (it seems Christine) fired him from the band a few years ago. I doubt it actually had anything to do with "musical" differences re: their tour or such.