Al Gore Responsible for Murder-Suicides?

An Argentina couple killed themselves and one of the children (and attempted to kill their daughter who survived 2 bullet wounds) over concerns about global warming. If civil laws allow assorted hate mongers being liable for murders committed by unknown followers, should Al Gore be criminally liable for this? Rhetorical question. (Answer, for those who don't know, is No. And neither should other speakers be liable when some listener takes their words too far.)

http://michellemalkin.com/2010/03/01/al-gore-is-not-responsible-for-those-alleged-global-warmicides/