I was going to say something about the hose play, but never did. I mentioned it years ago when Asha got nuts about the water hose. She didn't have loose stools but the intensity of the hose became crazy-making. As much fun as it seems to be for them it is mentally frustrating because they cannot grasp it. Biting water gives them nothing to grip or shake. The laser light toys that were so popular for cats years ago were found to be detrimental to their mental health. Prey drive needs to be rewarded with a catch, hold and "kill" (shaking the rag).
With Peppers stool afterward I'd attribute it to extreme stress and call the water hose play history.