No, no, they're not. What's the difference between a bug and a variation or an imperfection? If you think about it, if you make a small change to a program, it can result in an enormous change in what the program does. If nature worked that way, the universe would crash all the time.
Besides sounding like a plot device for a Douglas Adams book, it's a great point.
I've said it before: I sometimes feel like we're missing a LaPlace transform for programming.