The article was well-intended, but it makes it sound like painters are the crooks and consumers are innocent victims. That is blatantly un-true. Maybe there should be a follow-up article that educates consumers how not to be shysters by expecting a ton more than they said at the start, or not paying the balance of the job unless something else is done that was not in the contract. Tradesmen have a rough road when dealing with consumers that have short arms but long lists of by-the-way items. No, I'm not a painter...
Oh, where to begin? Let me start with 'watered down paint'. 25-50% before the material gets to the site? Impossible. You would basically be painting with water at that point. It would be less of a hassle, and cost, to simply use proper material. You would be forced to apply three coats instead of two, as the coverage would be horrible. Whatever cost you think might be saved in materials would be lost in labor.

House Painter