My family owns around 200 properties throughout the Seattle area that they flip/rent, so my childhood consisted of shadowing a master contractor until I knew it all. I’m an expert at everything that goes into building a house—from the foundation, to framing, HVAC, plumbing, electrical, drywall, finish work, etc. You name it and I’ve done it. I take pride in my work and once it’s fixed, it’s fixed.
Back to the article. You can add water to all latex based paints / thinner to oil based paint. The tinting base has absolutely nothing to do with it. Say you are working outside and throughout the day you have to add a little water to keep the same consistency. If somebody really tried to add 20% to 50% water they no longer would be painting they'd be performing a whitewash or pickle finish.
I managed commercial construction projects for many years, have built and remodeled several properties, and never once have I encountered any of these scams. The tone of this article is deeply troubling. The author seems to be saying that ALL painting contractors are inherently dishonest, and that has not been my experience. The underlying advice here is sound: get it all in writing and cover as many contingencies as possible--so pointing out potential pitfalls like coat coverage is helpful. But do that in the spirit of clear communication of expectations, not with the expectation that the person you are hiring will try to cheat you at every turn. Not every contractor takes outrageous advantage of change orders; not every contractor will sneak past necessary preparation and/or repairs. Contractors of all sorts get a bad rap as it is; reinforcing a stereotype with articles written from this point of view just seems unproductive.
Did you even read the article? It was specifying UNSCRUPULOUS painters! And, by the way, the photo at the top was not identified at all. How would anyone know whether it was done by a homeowner or not? Also did you ever stop to think that if a consumer has the knowlege to spot a dishonest contractor then by default he also has the knowlege to identify an honest one as well? And, pardon me, but just because you've never seen something has absolutely nothing to do with whether it has actually happened to someone else. Why would any honest business person be so defensive about the publishing of such useful information? If any painters/painting contractors object to a consumer having this kind of information maybe they are the dishonest ones!