I do not like the looks of that....what will most likely occur if you leave it is this....everything yellow will die, and rather than just dying, it will creep thru the rhyzome to the next psydobulb and kill that one...ect.
personally, I would sterilize my knife and scissors and get to work on that one....cut everything off that is yellowing. examine very closely the center of the cut rhizome. if there is any thing left, you can isolate the remains. I do not pot such a thing as I want to check it frequently. I drop it in an old coffee container with a bit of pea gravel in it....snip all the ugly roots off. spray often as you can think about it with a physan 10% solution. any time you see any more of the yellowing cut it again.
most times the plant wil die....I have saved a few plants this way, and its interesting to see nature unfold...good, bad, and ugly...its natures way...
please do not hesitate to experiment, you learn a lot by doing so.....but this is the reason you have to isolate new plants for a month or so....its a sneaky bacterial rot....I depend on physan a lot, and its big brother, photon....I use that at least twice a year, just to make sure nothing is fomenting in my collection....