It's funny we were just having this very conversation on another thread
here yesterday and I was told I was a "snowflake" for suggesting someone get a dashcam to prevent or at least catch actions like this from service technicians.
I was just waiting while watching that video for a car to pull out of a driveway or a kid to step out between some cars while the tech was flooring it. Also reading the comments by the poster on Reddit the garage he took the car to didn't seem to give a damn about it either, I am sure it wasn't the first time it's happened there. All the more reason to protect yourself. Thanks for sharing.