That is a problem for the lawyers and any expert witnesses they can find to solve. If such a thing cannot be proven beyond a reasonable doubt (if we are talkin

That is a problem for the lawyers and any expert witnesses they can find to solve. If such a thing cannot be proven beyond a reasonable doubt (if we are talking criminal charges) or beyond a preponderance of the evidence (if we are just talking about a lawsuit), then the case would not go through. If it could be proven, then such cases should be permitted. We are actually quite good at tracing infections back to their source, but that is not my specialty.