I'd be keen to see what he thought was crooked - 1/64" is about 1/3mm, and virtually imperceptible with a tapemeasure to most people, compared with parralax error from looking slightly sideways.
1mm off is no big deal, 2mm, tolerable unless it is blatantly near an edge or something. I wonder if the new job is any straighter?
But to answer the original question: I've fired three customers, and gee it was good.
The money I lost was tremendous, and the chance of winning in court was very high, but none allows for the time lost/wasted, and stresses involved in the process etc. I did the court way once, won, and still got only 1/3 of what I was owed, when they disappeared, then went bankrupt. In hindsight my loss would have been less, if I'd just ignored it and moved on.