If you think it got too wet knock it out of the pot and look at the soil and roots, find out if that is in fact what happened. If things turn out to be soggy, smelly and rotting that will confirm your impression. If the roots have rotted tree will not be likely to bounce back; condition of top described does sound like there is serious deterioration also.

In general with plants if the top suddenly goes bad the first thing to do is look at the roots, when there is not an obvious problem with the top only such as heavy bug infestation or chemical injury. Otherwise: as the roots go, so goes the top - the roots are the more critical half of the plant. That's why when you cut a plant off at the ground it may grow back from the roots or stump, but the cut off top is liable to lay there and die.

When you remove the plant from the pot, if you find rotted roots, go ahead and cut them back to a healthy portion of the root before repotting in fresh, well-drained medium.