I had occasion to use FireWatir recently and found a strange bit of behavior trying to manipulate a select_list element. I posted an executable bug report to the Watir-general mail list. (Please read the whole (short) discussion.)
I have not been working closely with Watir for some time, so I missed some obvious diagnostic paths. Even so, though I got a reasonable explanation for the observed behavior, I pushed it farther, wondering why I did not receive a NoMethodError trying to do what I did.
Please note: at no time did I ever editorialize; nor criticize; nor invent solutions. I merely discussed observed behavior with interested parties in disinterested tones. And upon examination, I had turned up not one, but two different bugs.
I am pleased once again to have contributed to the Watir project. Furthermore, I think the discussion linked above is pretty close to a Platonic ideal of bug reports.