I hesitate to admit this, but I did that exact thing with a rake once. It was leaning against a planting mound, which tilted the tines enough for me to step on them easily. The rake was in plants deep enough to hide it well. I had just enough time to turn my head before the handle of the rake slammed into it hard enough to make my ears ring. A wholly unpleasant
experience, but one that taught me the lesson of not leaving tools lying around like that in a single event.