Doing a little sleuthing it seems like it may be slightly overstating things to say he was a member or leader of Hezbollah, more like a spiritual mentor or a cleric closely associated with the movement. In any case, given CNN's record of running for the hills over a lot less, I can't say I'm completely surprised at their decision. And I'm a little surprised she'd tweet that myself. And in the internal memo CNN circulated explaining her termination, a CNN VP wrote, "she fully accepts that she should not have made such a simplistic comment without any context whatsoever."
But a twenty year run down the tubes over 140 characters?
That just doesn't seem right to me.