I've been doing some googling -- there's remarkably little reportage on this most recent incident (thanks to the "journalists" at the LA Times), but you can find a fair number of unreslved questions from the Chatsworth crash. Among them, how the engineer was hired with a shoplifting conviction.

And I'm still wondering how any sort of diligence in supervisory checks could not have exposed habitual practices like texting -- the engineer did this all the time. I would guess that the two guys in the cab in Rialto will also come up with odd behavior. I just don't see things like this happening out of the blue. Our "journalists" should be following this.