Sometimes we can only hypothesize how a person with a terminal disease will feel... unless we ourselves are struck with a similar situation, it is not easy to assume. There are many facets to a person's persona and state of mind. There is also the workings of karma that nudges a person towards a certain direction given the frame of his or her mind at the time.
Hence in the story above, if Lama Zopa says its good karma, I believe him but let us not bundle every person who is suffering from a terminal disease as someone who has the ability to see it as such. There are many factors involved, some of which could turn a person towards an opposite path... seeing the fragility of life can also mean the perception of the lack of time hence it could well trigger an acceleration of self destruction from anger and fear. I have heard of many examples of both...
So what makes it good or bad karma I feel is how the situation is perceived. The root of the matter could well be a fruition of bad karma to have to experience a terminal disease but if one takes it as a "blessing" that very seed is turned to something good... incredible how impermanence permeates in all aspects of our lives!
