Very glad to hear you escaped relatively unscathed from such a horrendous event! Way too close a call. One of my customers rode their zero-turn down into an extremely steep sinkhole a few days ago, both mower and operator somehow emerged unscathed.
When a ZT starts to slide, it is near impossible to recover - at that point you are merely an unwilling passenger. And yes, I've had to get the tractor to pull mine out of the pond a couple times, when "just one more pass down a little lower", was one pass too many. Never had it where the water depth got up past the top of the deck, though.
You're lucky. And great job keeping your wits about you, your ability to remain calm probably helped save your life.
