It was a very healthy plant with a very good root system. It has also finished maturing its last growths. Removal of the old rotting growth and letting the plant breath and dry out would have been more than sufficient, and may be application of a topical fungicide to the cut part like sulphur powder. It is important to let the plant be dry, there is no faster way of killing a catasetum alliance orchid than keeping a plant headed for dormancy always wet. Good luck.