I'm not sure of the issue but misinterpretation of test results can be an issue. There was a case a few years back of mustard contamination of wheat. We were asked by a customer if we needed to alibi label. On reading up on it, I genuinely felt that the results were likely to have been misinterpreted from a false positive resulting from rape seed oil protein not mustard and also, if present, the levels were likely to be tiny.
We did some due diligence testing, never found anything and so didn't alibi label figuring that genuinely we had higher risks around us.
It would be interesting to hear more info about the case you talk about if you have it?