[Cynthia, Prescott, AZ]

Often times when a leaf has this kind of a problem, the rot travels down the leaf to the psuedobulb and ends there. If the section came out easily, it probably is repeating this pattern. I would wait a little longer to see if the problem continues into the new bulb, which it may not. You may want to cut the outer sheathing off further down to expose the good tissue of the bulb. Purpurata is monofoliate, so that was probably the entire and only leaf the new growth had, and now there is only a bulb inside the sheathing. But, the sheathing is living tissue, tho it will be short lived, so use a sterile tool again.