I had a lovely example of one of Fluffy's most annoying traits. In my (far too lengthy) experience handling user support requests I have found that there are people who will intentionally not give you all the information needed to solve a problem. They will give just enough so that you think the problem might be one thing. Then, when you start giving them your theory on the problem, they proudly pull out a new piece of information that your theory didn't account for (since it was formed before you were told about it) and declare smugly "well, what about this?" It seems they almost are holding out just so that they can rub your face in your theory being wrong.
Fluffy, being someone who seems to take delight in the mistakes of others, does this reflexively.
Today he handed me a sample of a couple of boxes that were printed. There was a problem where the process was not printing the correct final four digits. His theory was that they were repeating the four digits just previous in sequence. I looked at the last four digits, which were 4501 and 4502. Knowing that the printers are generally designed to just add one to the last number printed -- we are overriding this behavior in this particular application -- I suggested that he try printing one more box, and see if it came out 4503 or not.
"Well..." he said, and moved his hand to show what he had been hiding there. In his hand he held three more boxes that had been printed as part of this process. All three of them had the last four digits read 4501.
"Oh, you were holding out on me," I said. "You could have showed me that earlier."
"I'm showing it to you now," he replied with a laugh.
"Were you intentionally holding out on me, just so that you could pull them out later and trump my theory?" I asked. The tone (hopefully) made it sound like I was joking.
He fumbled out some lame excuse, and I let it drop. Still, ain't he a charmer? Let's withhold testing information so that the programmer cannot make an informed analysis of the issue. Isn't it funny when they come up with the wrong one? Ha, ha, ha.