Terry, I never had an incident quite like that. But had one of similar consequence. The current dog and her cat (Dizzy and Lincoln) enjoy chasing each other through the house. The cat also likes to hop out on top of the hot tub. It's a sunny place to set.
One evening as the dog and cat were wagon training through the house I have a friend over. We found our way to the hot tub and, of course, just before I hear the "splash" I think "oh man I hope the cat realizes the cover is open."
The friend suddenly had freaked out scratching cat beneath her. She got mammarily scratched and was not a happy camper. Unfortunately my first reaction was to think the whole thing was just funny as hell. So she was pissed and I was laughing my ass off. Soon I needed a bigger dog house than the dog or the cat.