Somewhat similar to a recent Black Hills Monitor post there was an indication of uncertainty and skepticism. The letter concluded (emphasis mine),
If the global warming science has been discredited (as appears possible), why would anyone choose to ignore that?
However, the balance of the letter points to the writers not being so much skeptical of the science as searching for whatever reason to reject the science of climate change and thus any action against it. The writers' supposed skepticism does not extend to "reports of manipulation of global warming data" and "cap-and-tax legislation."
The game being played by the letter writers is a favorite of the denialists and rejectionists - declare there is (or even just may be) some doubt and assert that therefore action against climate change (of course phrased in demonized terms like "cap-and-tax") should be put on hold. They will say that if we do not really know we should keep sitting on our hands.
The biggest flaw with that tactic is that this manufactured uncertainty does not actually exist. The story remains the same - overwhelming scientific evidence and thus consensus points to human activities largely through greenhouse gas emissions having a detrimental effect on climate and the environment.
The Martinis' letter is another attempt to make a mountain out of a grain of sand, to declare climate science suspect because of some poor behavior that in no way affects the science. Sure, if the science would suspect it would be reasonable to reassess whether limiting carbon emissions mattered. That is exactly why so many make so much effort to try to pick at the science and find anything they can that they think can be waved about as the reason to declare the science suspect. The fundamental science, the bolded in the paragraph above, is not suspect.
What is flawed are the tries to undercut and undermine that fundamental science. There is a twist on a saying that goes, "If ifs and buts were candy and nuts, we'd all have a merry Christmas." Part of the mission here is pointing out how empty the ifs and buts (like the Martinis' "if the global warming science has been discredited") really are.