Liberty Mutual Commercial: Absurd

Why wouldn't this woman stop this dude from walking in front of a truck?  The point of the commercial is to encourage people to do good things for others, but if you need encouragement to stop someone from walking in front of a bus, you're beyond help.
Also, what is that idiot doing walking with headphones blaring and head down into a crosswalk?  Maybe I would let that dude walk in front of a truck.  Because he's an idiot.