Even though there are a lot of painters out there that insist that the newer latexes don't flash, I still work to keep a wet edge and cut just ahead of rolling. I feel that this is especially important for the final coat; I don't worry about it for primer or the first coat of multiple-coat work.
I think you've stumbled upon the approach that a whole lot of painters seem to be taking these days: pushing the envelope to see what they can get away with. They'll do a quick and dirty job and if they get away with it, they've made great wages. If they get "busted" as happened with your guys, they'll come back and do another coat. Most of the time, the clients don't care or don't know the difference.
Years ago, I had a mentor in a previous line of work who had a motto:
"If you don't have time to do it right, when are you going to have time to do it over?"
That's an approach that's stuck with me.