Parking brake only works when you use it

The first morning of our 48hr shift is a busy one. We have a lot of paperwork, rig checks, daily routine and some maintenance issues to attend to. The other day we were in the middle of this routine when a large, older white man walks through our employee parking lot and straight into the station. He stood out on account of his skin color but also he was wearing coveralls. I was near the door so he approached me and asked if anyone owned a toyota truck. I had to think about it, but I remembered the station captain owns an older 4runner that could pass for a pick up with a shell. I advised the visitor who owned one and asked why. He replied in a tone that let me know he was less than impressed with whatever had happened: "because it just hit my truck!" I look out the back of our station and almost one block away, in the neighboring parking lot that is on the other side of a street; is the captains truck wedged in between the rear wheels of a large semi truck. Apparently our beloved station captain had forgotten to put his truck into gear or set the brake. I will skip the response that we got from him when we told him. But his truck had reversed out of our station parking lot (without hitting any of our trucks. remember this is shift change so the lot is packed.) crossed the street, made a gentle turn to access the driveway and across the parking lot that is a full city block. We thought it was hilairious. He wasn't impressed. He was even less impressed with one firefighter who chocked the 4runner once it was returned to its original starting spot.