I had this guy in Phoenix hold a tape to my layout line and say, 'you're off a quarter inch, that's a fail.' He was right, and it ate my whole afternoon redoing the forms. Has anyone else had a customer check work with their own tools before you even get the float out?
My buddy down in Tucson ran into this last spring on a driveway pour. The homeowner came out with his own level and started checking the slope before the concrete truck even showed up. My friend had to tear out two forms and redo them because the guy was right about the grade being off. He said the worst part was the guy stood there the whole time watching him fix it. Now he keeps a cheap torpedo level in his truck just so the customer can check it with his own eyes and feel good about it. Saves him a lot of grief when the guy thinks he found something first.