I suspect that the dire prognostications are correct, sorry to have to say. Otter boxes are all very well but won't fit in a hip pocket, this in itself might prevent it falling in the loo when you drop your trousers before evacuation. If you think that you might make the same error again, go to a marine store, where you will find all sorts of waterproof bags, and you can still use your cell phone while it's in said bag.
John