I write software. It is sometimes imperfect. I become aware of imperfections by issues that are opened (or reopened) in a Bug Tracking system.
There's a sense in which a software issue is like a crime and a sense in which it is like a disease. My two favorite television shows, Law and Order: Criminal Intent and House show the detective and doctor solving problems much like a software engineer diagnoses and fixes bugs. (Yes, it is better if bugs are "designed out" ahead of time, but that's another post.)
Bug Tracker issues should be "phenomenological" focusing upon the outward indications of incorrect behaviour of the system in question. However, similar phenomena can arise from diverse failure mechanisms.
For instance, one can have pock marks on one's skin from Chicken Pox or from Measels. Though the doctor would like it if both maladies received distinct bug tracker numbers, he can't count on that. As the fictional Dr. Gregory House would say, "Patients lie." He is unfair. Patients reflect phenomena and it is his job to see past phenomena to underlying failure mechanisms.
The challenge of a bug tracking system is to accurately track observed phenomena and root failure mechanisms. Bug Tracker does a good job of the former, when I'm smarter, I'll suggest something to address the latter. Perhaps the software engineer should look to the medical or the forensic communities for patterns to apply to this problem.