There are many possible reasons why LNT may not be exactly right, but misrepresenting it as anything else than the current best assumption is dishonest in my opinion. I am not aware of hard evidence contradicting it. Overall, evidence is consistent with linear risk at low doses and this is also consistent with plausible mechanisms. Even with LNT we do not expect "cancer clusters" in regions higher background radiation. We would expect a small excess number of cancers on top a huge amount of cancer we have anyway. This is statistically difficult to detect and there many other possible confounders. Regarding the original article, terminology such as "LNT worshipping" is a clear sign that sources are pseudoscientific.