I'm working with a younger guy who started his own business about 3 years ago. The business is a hardwood refinishing business with installations to boot. I myself have been doing floors for about 21 years, and have been doing finish carpentry also for roughly the same amount of time. The guy im working for has only been doing floors for 5 years total ( I know this because he told a customer he had 5 years experience, should have seen the customers face.) Recently he has become overly picky about very minor flaws in my work. I'm talking about very small cracks ( maybe a heavy 1/16th) which require some filler. I installed a custom tread with nosing, a brazillian cherry border with red oak inside the border installed on a 45°. I happened to cut one piece of nosing short by mistake and didn't have enough material to fix it so he had to purchase another to replace it. Understand that this guy had me do this work because his skill level wouldn't suffice. So he preceded to question my ability, and stated that the next time it would come out of my pay. Needless to say I was boiling mad, but held my tongue because I need the work. I have NEVER had one of his customers complain about my work. They are always satisfied when we leave. I have even tried to help him improve his business by offering to do some trim work and some staircases when we are slack on flooring work, but he won't take those jobs because he hasn't a clue how to do them himself. I guess what im asking is, does anyone have any ideas how to deal with this guy?