The Power of Negative Thinking
Let's say that a telecom tower was built in your neighborhood to broadcast microwaves at a new frequency. Then, after it was up and running, neighbors began claiming all sorts of ailments including rashes, headaches, nausea, tinnitus, sleep disruption especially among children and gastrointestinal upsets. Finally, following protests from "a residential community filled with children exposed to uninvited microwaves", the company shut off the tower. Thereafter your neighbors reported that their symptoms had improved dramatically or had disappeared altogether. What conclusions would you draw about the new microwave tower and the risks it poses?
Now let's say that the company announced, and proved, that the tower hadn't been "ON" in the first place. Would that change your conclusions? Well, that's exactly what happened here.
We used to have all sorts of fun like this back in the days of multiple chemical sensitivity and similar litigation. The plaintiffs' lawyers though learned to discover everything there was to discover about a defendant's operations first and only then present their witnesses, prepared for all such revelations and ready with new and unfalsifiable claims, for deposition. Alas.