Private chat clients are used for private chatting. While no one is there to stop you from exchanging the information away from the JCF, it is still regarded as a secret. This case falls in the gray area. I don't know if the person wanted you to share the information (no request was shown), but then again, you can only assume the worst. Of course, you wouldn't know if I would assume the best or the worst, so in the end, what was done could never be considered a "mistake" or anything worse. Rather, it was simply a mismatch of expectations on both fronts.