Just a simple oil change. The technician actually lost an oil fill gasket. But he pointed out the problem, detected an oil leak on the floor and called me back in to diagnose. He had to disassemble some engine cowling, but found the gasket, washed the engine and instructed me to monitor the issue and come back in if it wasn't resolved. I wish it hadn't happened, but it was an older gasket that could have happened to anyone. I appreciate the integrity of everyone involved and that I am not at risk of being stranded miles from home.