Maybe, maybe not. There’s also a bankrupcy, a foreclosure and a marital separation involved. Doubtless, paternal possessiveness may be involved as well, but “honor killing” usually doesn’t involve gunning down whole families. Maybe Geller is right, but it’s best to wait for the full story before slapping a label on it.
I think all of the circumstances of the case are of a piece with the mindset of many Muslim men in this era of jihad. There's a distinct possibility that all of the events that were collapsing this man's life, served to catalyze his already warped view of the world.
One thing is for sure - he was out of his mind when he perpetrated the act.