The dumpster thing reminds of a job we did. The GC had a dumpster on site for everyone to dump their garbage into. What we didn't know is that when the guy came to pick it up the dumpster the Superindentant would go inspect the dumpster. He would analyze the garbage and decide how much was from each trade. 25%-electrical, 30%-plumbers 20%-stucco etc. A couple of months later we started getting back charges for "our percentage" of the dumspster.

They did the same thing on the scissor lifts. Everytime we would use one of the so called community lifts he would make a note and then back charge us for however many days we used the lift.

We don't do work for that GC anymore.