There was a contractor that was laying a deep wastewater line around on the East Side of San Antonio. It was deep in the ground. The owner of the company would come to the job every few days and express his displeasure with the progress. No matter how many joints of pipe the crew installed, the boss man would complain.
Finally the crew decided that every time he came out and tore them a new one, they would leave a few gaskets out of the next pipes they laid.
When they finally got to the end of the line and everything was cleaned up and nothing but testing the line was left to do, they all quit and moved on to greener pastures.
A new crew was hired to do the testing. It was impossible to get the line to pass the tests. In the end most of the line had to be dug up an re-laid, causing the contractor to eventually file bankruptcy.
It never hurts to be friendly and make sure the men working for you are on your side.