Reliability is a quantitative concept that generally means that there will be little variability from one data collection to the next. In qualitative research, we accept that context will often create different results. Even if two different researchers use "exactly the same" data collection and analysis procedures, they may well reach different conclusions.

I gather that in qualitative research the focus is on credibility rather than reliability. But within the same study corroboration of results by different participants enhances the reliability of qualitative data or for that matter the credibility.