Seeing that the reversal step is incorporated in the color developer, I find it rather interesting that color development did take place, but not (adequate) reversal. What could have rendered the reversal step ineffective, while the color developer still worked? Some form of contamination? Or can the reversal chemistry actually become exhausted sooner than the color developer itself? And what if the two parts of the CD concentrate weren't mixed in the correct ratio, or one part totally omitted? I know this is pretty much all speculation, but I am intrigued by what could have happened, and perhaps it could even give the OP some clues as to what went wrong.