While the bath is remodeled

Monday, the first day of the bathroom remodel:
D, the demo guy, comes running down the hall way with a look of panic on his face. I hear rushing water. D mentions water, turn off, and races out the front door. Gary cant figure out what D said or why he was running outside. I immediately went downstairs to turn the water off, came upstairs and looked outside and saw D underneath the juniper looking down into the main water line box. I calmly told him that I shut the water off. He came back into the house covered with juniper and dirt but much relieved. Dare I ask him why he would try to dismantle a shower valve without turning the water off.