Why did the man mowing his lawn start throwing up when a plane flew over and cast a shadow on him?

The man mowing his lawn likely experienced a sudden wave of nausea triggered by the shadow of the plane, which could symbolize a fear of flying or an anxiety response. Alternatively, the unexpected shadow may have startled him, causing a physical reaction. It's also possible that he was already feeling unwell, and the sudden change in environment exacerbated his condition.