The behavior you describe is its own antidote for a normal person. A narcissist would blame the client. A sociopath would grab some nearby colleague and throw them under the bus.
May I suggest that the trouble with narcissists is the efficiency of their thought processes: They only have to think about one person at a time...one person ever. That makes them more efficient mentally. Also, people who can't see themselves have no self-doubt. That makes them better, more efficient leaders. Also, people who are good-looking are more likely to develop these traits, and, having developed them, are less likely to have to go away and sit quietly by themselves and unlearn them.
I'm speaking from experiance. I've had narcissistic, sociopathic, and "other" SOs. The Sociopaths are most fun because they don't have any fear. The narcissists are the next most fun because they tell jokes better (attention) and they try harder to get praise (attention) and they are better conversationally and socially.
Ultimately? I would not go back. I like to get a massage, instead of having to give all the time, for example.
But let's call a spade a spade: Good looking and fun? check! No self doubt? check! Hot in the sack? check!
That's hard to learn to say no to. It takes practice, and really, to make yourself not answer the phone there has to be baggage to create that strong "I don't think so" reaction.
My examples are from personal life, but similar themes apply at work and socially. Narcissists are more popular and harder to create momentum against. They are more glib, and get away with talking first and longest. It takes conscious effort and practice to get a word in and certainly if there are cliques in place, it may take effort which is not going to see long term payoff to defend a position or create momentum without a narcissist getting on board to bring the group.
Is this a cause or a symptom of the founder-hacker/salesman-CEO devide?
The thing about lists of habits is that they supply their willing victims with a prima fascia choice: Do as the others do and abandon integrity or ignore me (or us) and stick to what your whole life up to this point has tought you.
How does it differ from "monkey see monkey do"?