Wait, so are you saying that we should be more outraged when business models and customers are stolen in a borderline illegal way? This is a valid point and we probably should be more outraged.
Or are you saying that it should be ok to rip off someone's design and hotlink to their assets?
I think that's pretty highly dependent on the individual. There's an article about the surgeon Charlie Wilson who slept around five and the half hours a night and yet excelled at his craft.
I think that rather than asking you to lie habitually, he actually meant that you should express gratitude in such situations. As far as social and business norms go, thanking someone for a lead and saying you'll follow up as soon as possible (even if that's unlikely) wouldn't be considered lying, unless you're being overly pedantic. =)
It's also hard to see how this advice wouldn't be the optimal behavior in most or all situations. Almost all the time, communication is as much about how the communicators make each other feel as it is about the information being communicated - hence the smiley in the previous paragraph. =) The advice in the article is just trying to point that out in the case of someone offering you a sales lead.
http://i.imgur.com/MXCuN.png
You going to take that down also?