According to Ben Wojdyla, one of the mechanics in the video, a Mercedes-specific spring compressor failed in operation, resulting in a very close call.
The moral of the story? Don’t trust coil springs. They can fail. And if you’re going to replace them, make sure to take the proper safety precautions, including wearing safety glasses and securing the compressed spring using a jack or chain before removal.
Here’s a good video for safe removal of a front coil spring.