I think it was Trish and Rob who were doing the "talking past", by trying to change the subject from simple sea level measurements to polar bears and experiences of flooding. It was clear Trish and Rob didn't want to stay with the sea level measurement topic, and I think I know why...
If I had to look at it from their perspective, they may have reacted the way they did for the same reason I react the way I do to certain skeptical arguments against psi. For instance, someone could say, "there is no evidence of any kind of mechanism by which psi can be achieved." I would likely respond that "lacking an explanation doesn't rule out evidence of the phenomenon. For example," and then I would provide an example from my personal experience.
The difference to that hypothetical reaction and the MacGregor's reaction to Alex is that my reaction includes evidence for psi. Their reaction did not include evidence for climate change. A local flood, even if repeated annually for a few years, does not prove climate change. One sound example of psi does disprove the position that psi is impossible.
It is possible the MacGregor's believe that their local flooding and inaccurate knowledge regarding polar bears does constitute evidence of climate change. In that case, their reluctance to engage Alex was disappointing. In any debate, if your evidence is questioned, it is time to re-examine the evidence in light of the criticism. If the analysis of the evidence is the problem, then the analysis can be debated. The MacGregors refused to consider that their "evidence" was either wrong, or it was wrong to use that evidence in the context of debating climate change.
The Amazing Randi once told a mutual acquaintance that I must have been tricking him somehow into believing I had psi ability. He then ran down a list of ways I could have done this. However, my friend knew me and the facts too well to accept any of Randi's hypotheses. If he hadn't known me or wasn't personally acquainted with the relevant facts, Randi's arguments would have been much more compelling. An irony is that my friend has always been a skeptic of psi. He happened to become a witness to several events through our friendship, and wanted Randi to explain his observations. Randi couldn't give him a credible possibility but only because my friend knew the details firsthand. If he hadn't, he likely would have accepted Randi's explanations as valid.
The MacGregors believe they have the evidence because they have been told that, for instance, local flooding is evidence of climate change and they have personally witnessed local flooding. One might as well say that blood on the sidewalk is evidence of murder. It might be evidence related to a specific murder, or it could be evidence that someone wearing shorts fell off his skateboard and skinned his knee.
“One of the bits of knowledge that John Audette [who later became a cofounder of IANDS and its first executive director] imparted to me late one evening struck me quite forcibly. He told me that he had met a few people whom Moody had first interviewed, who all independently seemed to have had a vision of the planet’s future in conjunction with their NDE. That in itself wasn’t so astonishing, of course, but what John went on to tell me was of more than passing interest. All of them, he said, had had essentially the same vision and that it was one of widespread and cataclysmic destruction. Furthermore, they all appeared to agree on the year in which these events were to take place. The year was 1988.”